4 .,

IAWA LIST

OF MJCROSCOPIC FEATURES FOR

HARDWOOD IDENTIFICATION

byan

IAWA Comnilttee

E. A. Wheeler, P. Baas & P. E. Gasson (editors)

k

IAWA LIST OF MICROSCOPIC FEATURES

FOR HARDWOOD IDENTIFICATION

with an Appendix on non-anatomical information

IAWA Conirnittee

Veronica Angyalossy Alfonso - São Paulo, BrazilPieter Baas Leiden, The Netherlands

Sherwin Carlquist - Clareniont, California, USAJoao Peres Chirnelo São Paulo, Brazil

Vera T. Rauber Coradin - Brasilia, BrazilPierre Déiienrte - Nogent-sur-Marne. France

Peter E. Gasson -. Kew, UKDiciger Grosser— Miinchen, FRG

Jugo lhe - I-lighett, Victoria, AustraliaKeiko Kuroda Kyoto, Japan

Regis B. Mifler— Madison, Wisconsin, USAKen Ogata - Tsukuba, Japan

Hans Georg Richter - Hamhurg, FRGBen L H. ter Welle - Utrecht, The Netherlands

Elisabeth A. Wheelcr Raleigh, North Carolina. USA

edited by

E. A. Wheeler, P. Baas and P.E. Gasson

© 1989. IAWA Builetin n.s. 10 (3): 219-332Puhljshed for the International Association ofWood Anatornisis at ihe

Rijksherbariam, Leiclen, The Nerherlands

221

PREFACE

This list of rnicroscopic features for hardwood identification is lhe successorto lhe StandardList of Characters Suitable For Computerized Hardwood Jdentiflcation' published in 1981(IAWA Bulietin n.s. 2: 99-145) with an explanation of lhe coding procedure by R.B. Milier.

Thc 1981 publication greatly stimulated international exchange of information and experienceon characters suitable for hardwood identiflcation, and inspired considerable debate on lhe mostdesirable coding procedures and ideruiflcation programs. Therefore, aL Lhe IAWA mcetingduring lhe XIV inLernational Botanic.aI Congress in Berlin, July 1987, it was decidcd to revisethe 1981 standard list. Because oU Lhe continuing developments in computer technology andprograrnrning, ii was agreed to limit Lhe scope of lhe new list to dcfinitions, explanatory coni-rnentary, and iliustrations of wood anatomical descriptors, rather Lhan concentrate on codiiig

procedures.A new Committee was appointed by lhe IAWA Council to work towards Lhe new list, and

thanks to a substaruial grant from lhe USDA Competidve Research Granis - Wood UtilizationProgram (Grant No. 88-33541-4081), a workshop was held by lhe Committee from October2-7, 1988, in lhe Department of Wood & Paper Science, North Carolina State University,

Raleigh, NC. USA, under lhe joint auspices of IAWA and IUFRO Division 5. A preiiminary

list was prepared during lhe workshop. IAWA rnembcrs were invited to cornment on this list,and these comrnents helped with lhe final preparation of Lhe new li st. Pie hst presented here wasagreed to after review of subsequent drafts and extensive internal consuitation between conimo-

tee members.Although ihis list has 163 anatomical and 58 misceilaneous features, it is not a complete li,[

encompassing ali Lhe structural patterns that one can encounter in hardwoods. lnstead it is in-tended to be a concise list of features usefui for identification purposes. Also, lhe numbers assigned to each feature in lhe present list are not meant to be codes for a computer program, butare intended to serve for easy reference, and to help translate data from one program/database tu

another.Wood and wood celis are biological elements, formed in trees, shrubs, and climbcrs to fui! dl

a physiological or niechanicai function. Aithough there is more discrete diversity in wood struc-ture than in many other plant parts, there is also much continuous variation, and any auempt tociassify this diversity into well-defined features has an artificial eleinent. Yet we are confidentthat in Lhe feature list presented here ambiguity of descriptors has heen iimited to a minimiitn.and we hope that ali present and future coileagues engaged in wood and decripti\ ewood anatomy will find this list a valuable guide and reference.

The IAWA Committee:

VERONICA ANGYALOSSY ALFONSODivisão de Madeiras, I.P.T. Cidade Untversitaria, Sio Paulo. Brazil

PIETER BAASRijksherbariuni, Leiden, 'lhe Netherlands

SHERWIN CARLQUIST

Rancho Santa Ana Bo:anic Garden, Clarculont, Ca!ifornia, U.S. A.

222

IAWA Bulle.tin n..%., Vol. 10 (3), 1989 1 AWA List of microscopíc features for hardwood identification

223

JOAO PERES CHIMELODivisão de Madeiras, I.P.T. Cidade Universitária, São Paulo, Brazil

VERA T. RAUBER CORADINInstituto Brasiliero de Desenvolvimento Florestal, Departmento de Pesquisa, Brasilia, Brazil

PIERRE DÉTIENNEDivision d'Anaomie des Bois, Centre Technique Forestier Tropical, Nogent-sur-Mame, France

PETER E. GASSONJodreil Laboratory, Royai Botanic Gardens, Kew, U. K.

DIETGER GROSSERInstitui fiir Holzforschung und Holztechnik der Universitiit München, Miinchen, F.R.G.

JUGO ILICCSIRO, Wood Scicnce & Technology, Highett, Victoria, Australia

KEIKO KURODAForestry & Forest Products Research Institute, Kansai Branch, Kyoto, Japan

REGIS B. MILLERCenter for Wood Anatomy Research, Forest Products Laboratory, Madison,Wisconsjn, U.S.A.

KEN OGATAWood Technology Division, Forestry & Forest Products Research Institute, Tsukuha, Japan

HANS GE0RG RICHTERInstitui für Holzbiologie und Holzschutz, Bundesforschungsanstalt für Forst- und Holzwirt-

schaft, Hamburg, F.R.G.

BEN J. H. TER WELLERijksuniversiteit Utrecht, Instiruut voor Systeniatische Plantkunde, Utrecht, Thc Netheriands

ELISABETH A. WHEELER

Department of Wood & Paper Science, North Carolina State University, Raleigh, North Caro-una, U.S.A.

ACKNOWLEDGEMENTS

The IAWA Cornrnittee is greatly indebted to the following institutions and individuais:

The USDA Competitive Rescarch Grants-Wood Utilization Program (Grant No. 88-33541-4081) for financing the IAWA/1UFRO Workshop in Raleigh, North Carolina, and subsequentrneetings in London and Leiden by P. Baas, P.E. Gasson, and E. A. Wheeler.

The Department of Wood and Paper Science, N. C. State University for offering hospitaiityand facilities during the IAWA/IUFRO Workshop in Raleigh; especially Dr. C.A. LaPasha andMs. Vann Moore for help with preparation of the various drafts, and Ms. Milie Sullivan.

The Forest Products Laboratory, Madison, Wisçonsin, USA, for providing financial support

towards the printing costs of this special issue,

The Jodreli Laboratory, Royai Botanical Gardens Kew, UK, for supporting photographicwork, and providing facilities and hospitality during a mecting in March 1989 for the selection

of iliustrations.

The BaiIey-Wctmore Laboratory of Plant Anatomy and Morphology, harvard University,

and Dr. P. B. Tomhinson, Dr. D. Pfister, and Dr. A. Knoll for giving access to the Bailey nega-

tives and darkroom facihities.

The Rijksherbarium for various facilities; especially to Ms. Emma E. van Nieuwkoop for

mounting the plates, and lay-out editing.

All IAWA Members who have kindly given their comrnents on various drafts of this list:

K.M. Bhat, IndiaLim Seng Choon, Kepong, MalaysiaD. F. Cutler, Kew, UKW, C. Dickison, Chapel Hill, NC, USAT. Fujii, Tsukuba, JapanH. Gottwald, Hamburg, FRGMary Gregory, Kew, UK

AcknowuedgemefltS for iflustrations

Photograplis by courtesy of:

I. W. Bailey, Bailey -Wetmore Laboratory of Plant Anatomy and Morphoiogy, Harvard Uni-

versity: 10, 11, 16, 18, 39, 57, 58, 64, 65, 148.

Blumea: 38, 44, 73, 74 (Baas 1973), 174 (Van Vliet 1981).

P. Détienne: 129.P.E. Gasson: 2,4,7, 8, 12, 19, 21, 26, 28, 30-34, 36, 37, 40, 45-54, 63, 66, 75, 78-82,

84-86, 88, 90-93, 95-99, 102-106, III, 114-116, 118, 120, 122, 126-128, 130-

135, 137-144, 151, 153, 154, 156, 157, 159, 161, 163-168, 171, 172, 176, 178, 180-

182, 188.D. Grosser: 15, 27, 29, 55, 68, 71, 72, 112, 113, 146, 158, 170, 173, 177.

Yvonne Hemberger, Harnburg, FRGAlberta M.W. Mennega, Utrecht, The NetherlandsC.A. LaPasha, Raleigh, NC, USAA. Londono, ColumbiaPaula Rudail, Kew, UKM. Seth, india

224 TAWA Builetin nt., Vol. 10 (3), 1989

1 AWA List of microscopie features for hardwoodidefltiflCatiOfl 225

1 AWA Buileun: 3 (Bricigwater & Baas 1982), 35 (Vidal Comes ex ai. 1988), 70 & 123 (Bridg

water & Baas 1982), 155 (Topper & Koek-Noorman 1980), 175 Baas et ai. 1988), 184

(Gottwald 1983), 185 (Ter WelIe 1980).

J. lhe: 56.

C.A.LaPasha: 190.R. B. Milier: 160, 186, 187, 189.K. Ogata: 1, 5, 9, 13, 14, 20, 22, 24, 25, 41, 42, 61, 62, 76, 77, 83, 89, 94, 101, 107-109,

117, 119, 124, 125, 136, 145, 147, 149, 150, 152, 162, 179.E. A. Wheeler: 6, 17, 23, 43, 59, 60, 67, 87, 100, 110, 121, 169, 183.

H. P. Wilkinson: 69.

EXI'LANATORY NOTES

Quantitative FeatureS - For quantitative features of general applicability (e.g., vesselfrcquency, tangential vessel lumen diameter, vessel element hength, and fibre length), this listineludes broad categories for easy use when identifying unknowns, as well as more precisequantitative descriptors (mean, range, standard deviation). When constnicting a database thenutnbers of samples as well as Lhe number of measurements or counis done per samplc shouldbe recorded Different computer programs allow storage of different amounts of information(eg., ali measurements, orjust the means, ranges, and standard deviations), and use differentalgorithms for rnatching quantitative features. This publication does not recommend a particularprogram or a particular method for the storage and retrieval of quantitative data, but provides

some guidance on how to obtain these data.

Variable Features and Relative Abundance - l3ecausc of wood's inherent variabihi-

ty, it is inevitable that some fe.atures will be well-defined in some samples while absent or iii-defined in other samples of the sarne species. Accommodatiflg such variability has always beco aproblem in key constiUctiofl, and most keys (computerised or otherwise) have provisions forsuch situations. Describing relative abundance of some features, e.g., prismatic crystals, is alsoproblematic, and textual cominents on reiative ftequency should be added to a description ordatabase- In this list of descriptors, some features apply only when the characteristie is of com-moo occurrence. For such features, the illustrations and examples are intended to help interpret'common'. Although many keys have used these sarne features accompanied by the sarne quali-fier 'common', there have been no extensive systernatic analyses to determine what per centocçurrence constitutes 'common'. Therefore no quantitative criteria for 'common' have been

offered in this list.

226

IAWA Bulietin n,s., Vol. lO (3), 1989

IAWA.Listof microscopie features for hardwood idcntification

227

UST OF FEATURES

Name

ANATOMICAL FEATI:RES

Growth rings - p.234

1. Growrh ring boundaries distinct2. Growth ring boundaries indisiinct or absent

Vesseis - p. 236

Porosity p. 2363 Wood ring-poroiis4. Wood semi-ring-porous5. Wood diffuse-porous

Vessel arrangeinent - p. 2386. Vesseis in tangential hands7. Vessels in diagonal and/or radial partem8. Vesseis in dendritic pattern

Vessel groupings - p. 2429. Vesseis exclusively solitary (90% or more)

10. Vessels iri radial multiples of4or more common11. Vessel clusters common

Solitary vessel outiine - p. 24412. Solitary vessel outline angular

Perforation plates p. 24613. Simple perforatiori plates14, Scalariform perforation plates

15. Scalariform perfor'ation plates with ^ 10 bars16. Scalariforrn perforation plateswith 10-20bars17. Scalariform perforarion plates with 20-40bars18. Scalarit'onn perforation piates with ^ 40 bars

19. Reticulate, foraminate, and/or other types of multiple peiforatiori plaes

lnteri.-essel pus: arrangernent and sire - p. 25020. Intervessel pits scalariforrn21. Inrervessel pus opposite22. Intervessel pits alternate23. Shape of alternate pits polygonal24, Minute -25. SmaU - 4-7 rn26. Medium - 7-10prn27. Lrge - ^:lOi.tm28. Range of iniervessel pit size (m)

Vestured pits '- p. 25229. Vestured pits

Vessei-ray pirring - p. 25330. Vessel-ray pits with distinci borders; similar to intervessel pits in size and shape throughout

Lhe ray celi31. Vessel-ray pits with much reduced borders to apparently siniple: pits rounded or angular32. Vessel-ray pits with much reduced borders to apparently simple: pits horizontal (scalari-

forrn, gash-like) to vertical (palisade)33. Vessel-ray pits of two distirict sizes or types in Lhe sarne ray cdl34. Vesscl-ray pus unilaterally con'ipound and coarse (over 10 um)35. Vessel-ray pits restricted to marginal rows

Helica! thickenings - p. 25636. Ilelica] t1'iickenings in vessel elernents present

37. Helical thickenings throughout body of vesse] elernent38. Helical thickenings only in vessel element tails39. Helical thickenings only in narrower vessel elernei:ts

Tangential diameter of vessel lwnina p. 25Mean tangential diameter of vessel luniina

40. 2^50um41. 50-100nn42. 100-200 .riii

43. ^200p.m44. Mean, +1- Standard Deviation, Range, r - x45. Vesseis of mo distinct diameter classes, woçd no: nng-pero:s

Vesseis per square rnilürnetre - p. 25946, 5 5 vesseis per square millinieue47. 5-20 vessels per square rnillimetrc48. 20-40 vessels per square millirnetre49, 40-100 vesseis per square rnillimetre50. ^ 100 vcssels per square rnillimetre51, Mean, +1- Standard Deviation, Range, n = x

Mean versei elernent iengrh - p. 25952. ^350p.m53. 350-800 piri

54. ^800sm55, Mcan, +/- Standard Deviauon, Range. n = x

Tyloses and deposit.s ia vesseis -p. 25956. Tyloses common57. Tyloses sclerotic58. Gums and other deposits in heartwoxl vessels

Wood vesselless - p. 26259. Wood vesselless

Tracheicis and fibres - p262

60. Vascular/vasicenflic tracheids present

228

1\\vj\ OLilietin n.s., l(.) (i, 989

\\V.\ [_isL of nicroscpic caui tor Iidood

Ground tissue fibres - p. 26461. Fibres with simple to minutely bordered pits62. Fibres with clistinctly bordered pits63. Fibre pits common in both radial and tangential walis64. Helical thickenings m ground tissue fibres

Septate fibres and parenchyma-like fibre band - p. 26665. Septate fibres present66. Non-septate fibres present67. Parenchyma-like fibre bands alternating with ordinary flbres

Fibre wall rhickness - p. 26868. Fibres very thin-walled69. Fibres thin- to thick-walled70. Fibres vel'y thick-wallcd

Mean fibre lengths - p. 26971. 5900i.tm72. 900-1600 jim73. >1600j.tm74. Mean, +/- Standard Deviation, Range, n = x

Axial parenchyma - p. 270

75. Axial parenchyma absent or extremely rare

Apotracheal axial parenchynia - p. 27076. Axial parenchyrna diffuse77. Axial parenchyma diffuse-in-aggregates

Pararracheal axial parenchyma - p 27278. Axial parenchyma scanty paratracheai79. Axial parenchyma vasicentric80 Axial parenchyma aliform

81. Axial parenchyma lozenge-aliform82. Axial parenchyma winged-aliform

83. Axial parenchyma confluent84. Axial parenchyma unilateral paratracheal

Banded parenchyma - p. 27685. Axial parenchyma bands more than three celis wide86. Axial parenchyma in narrow bands orlines up to three cells wide87. Axial paxenchyma reticulate88. Axial parenchyma scalariform89. Axial parenchyma in marginal or in seemingly marginal bands

Axial parenchyma ceil type/srrand length p. 28090. Fusiform parenchyma cells91. Two celis per parenchyma sirand92. Four (3-4) cdlis per parenchyma strand93. Eight (5-8) cells per parenchyma strand94. Over eight cdlls per parenchyma sirand95. Unlignified parenchyma

Rays -p.282

Ray width - p. 28296. Rays exciusively uniseriate97. Ray width 1 to 3 cells98. Largerrays commonly 4- to lO-seriate99. Larger rays comrnonly> lO-seriate

100. Rays with multiseriate portion(s) as wide as uniseriate portions

Aggregare rays - p. 284101. Aggregate rays

Ray height p. 284102. Ray height> 1 mm

Rays of iwo distinci sizes - p. 286103. Rays of mo distinct sizes

Rays: celiular co,nposirion - p. 288104. Ali ray celis procumbent105. Ali ray celis upright and/or square106. Body ray celis procumbent with one row of upright and/or squarc marginal celis107. Body ray cells procumbent with mostly 2-4 rows of upright and/or square marginal cells108. Body ray edis procunibent with over 4 rows of upright and/or squarc marginal celis109. Rays with procumbent, squarc and upright cclls mixed throughout the ray

Shearh celis - p. 292110. Sheath celis

Tile celLs - p. 292111. Tile cells

Pe,forared ray cells - p. 294112. Perforated ray edis

Disjunctive ray parerzchvma ccli wall.ç - p. 294113. Disjunctive ray parenchyrna ceil walls

Rays per ,nillimetre - p. 296114, 54/mm115. 4-12/mm116. ^ 121mm

Wood rayless - p. 297117. Woodrayless

Storied structure - p. 298

118. All rays storied119. Low rays storied, high rays non-storied.120. Axial parenchyma and/or vessel elements sto:121. Fibres storied122. Rays and/or axial elements irregularly storie123. Number of ray tiers per axial mm

1\V,\ Bulk'tin r., 'Vol. li) ). 1)')

Secretory elements and cambial variants -p300

OU and mucilage celis - p. 300124. Oil and/or mucilage cdlis associated with ray parenchyma125. 011 andjor rnucilage cells associated with axial parenchyrna126. Oil and/or mucilage cells presem among fibres

Inrerceiluiar canais - p. 302127. Axial canais in long tangential limes128, Axial canais in short tangential lines129. Axial canais cliffuse130. Radial canais131. Intercellular canais of traumatic origin

Tubes / tubuies - p. 306132. Laticifers or tanniniferous tubes

Cambial varians - p. 308133. Included phloem, concentric134. Included phloem, diffuse135. Other cambial variants

Mineral inclusions - p. 310

Pris,naric crystals -p. 310136. Prisrnatic crystals present

137. Prisrnatic crystals in upright and/or square ray crus138. Prismatic crystals in procumbcnt ray celis139. Prismatic crystals in radial alignment in procumbent ray cells140. Prismatic erystais in chambered upnght and/or square ray celis141. Prismatic crystals in non-charnbered axial parenchyma cells142. Prismaiic crystals in chanibered axial parenchymacells143. Prismatic crystals in fibres

Druses - p. 313144 Druses present

145. Druses in ray parenchyrna celis146. Druses in axial parenchyrna cells147. Druses in fibres148. Druses in chambered cells

Olher crystai types -- p. 313149. Raphides150. Acicular crystals151. Styloids and/or elongate crystals152. Crystals of other shapes (mostly small)153. Crystal sand

Orher dia gnoszic crystal features - p. 315154. More than one crystal of about the sarne size per celi or chamber155. Two distinct sizes of crystals perceil or chamber156. Crystals in enlarged cells157. Ciystals in tyloses158. Cystoliths

1 .\\V1\ List ol nhicroscopic icatures fnr i irdocd dcnti:cr

Silica P. 318159. Silica bodies preseni

160. Silica bodies in rav colis161. Silica bodies in axial j cnchvnm c cis

162. Silica boclies iii fibres163. Vitreous silica

APPENDIX - Non-anatornical information p. 2 1

Geographical distribution - p. 321164. Europe and temperate Asia (Brazier and Franklin region 74)

165. Europe, excluding Mediterranean166. Mediterranean including Northern Africa and Middle East167, Temperate Asia (China), Japan, IJSSR

168. Central South Asia (Brazier and Franklin region 7)

169. India, Pakistan, Sri Lanka170. Bumaa

171. Southeast Asia and the Pacific (Brazier and Franklin region 76)

172. Thailand, Laos, Vietnam, Cambodja (Indochina)173. Indomalcsia: Indonesia, Philippines, Malaysia, Brunei, Papua New Guinca, and

Solomon Jslands174. Pacific Islands (including New Caledonia, Samoa, Hawaii. and Fiji)

175. Ausu'alia and New Zcaland (Bra7.ier and Franklin region 77176. Australia177. NewZealand

178. Tropical mainland Africa and adjaceni isla,ids (Brazier and Franklin region 78)179. Tropical Africa180. Madagascar & Mauritius, Runion & Cornores

181. Southem Africa (south of the Tropic of Capricorn) (BraLier and 1-ranklin region 70)182. North America, north of Mexico (Braaler and Franklin region $0)183. Neotropics and temperate Brazil (Brazier and Franklin rcgion 8 II

184. Mexico and Central America185. Carrubbean186. Tropical South America187. Southern Brazii

188. Temperate South America including Argentina. Chile, Uruguav. and S. Paraguav Brazicrand Franklin region 82)

Habit - p. 321189. Tree190. Shrub191. Vine/liana

Wood of co,nmerciai importance - p. 322192. Wood of commercial irnportance

Specflc gravity . p. 322193. Basic spccific gravity iow, S 0.40194. Basic specific gravity medium, 0.40-0,75195. Basic spccific gravity high, ^ 0.75

jmw-

232

IAWA Bulletin n. s. Vol. 10 3), 1989

1 A\VA. List nf rnicroscopic featurts for hardwocd identification 23

Hearwood colour - p. 323196. Heartwood colour darker than sapwood colour197. Heartwood basically brown or shades of brown198. Heartwood basicaily redor shades ofred199. Heartwood basically yeilow or shades of yeliow200. Heartwood basically white to grey201. Heartwood with streaks202. Heartwood not as above

Odour - p. 325203. Distinct odour

Heartivood fluorescence - p. 325204. Heartwood fluorescent

Warer & ethanol extracrs: fluorescence & colour - p. 326205. Water extract fluorescent206. Water cxtract basically colour!ess to brown or shades of brown207. Water extract basically redor shades ofred208. Water extract basically yeilow or shades of yellow209. Water exuact not as above210. Ethanol extract fluorescent211. Ethanol extract basically colour!ess to brown or shades of browri212. EthanoÏ extract basically red or shades of red213. Ethanol extract basically yellow or shades of yellow214. Ethanoi extract not as above

Frorh rest —p.327215. Froth test positive

Chrorne Azurol-S test - p. 328216. Chrome Azurol-S test positive

Burning splinter test - p. 328217. Splinter burns to charcoal218. Splinter burns to a fuli ash: Colour of ash bright white219. Spiinter burns to a fui! ash: Colour of ash yellow-brown220. Splinter bums to a fuli ash: Colour of ash other than above221. Splinter burns to a partial ash

NAME

Family, genus, species, authority.

When creating a database iL is essential to record the fuli taxonomic information on the speci.mens, i.e., record farni!y, genus, species, authority. For authorities foilow curnmonly used

abbreviations (listed in Mabberley 1987). Reference to Willis's Dictionary of Fiowering P!ants

and Fems(Willis 1973) and Mabberley (1987) is helpful in determining the farnilia) affinities ofvarious genera, and preferred fami!y names. When preparing a database, a!so indicate whichparticular classification scheme, with respect to fami!y delimitation, is heing used (e. o., Takhta-

jan 1980, 1987; Cronquist 1981, 1988; Thorne 1976).

li can be usefui to retrieve information on the wood anatomy of particular fami!ies or to re-strict the search for the identity of an unknown wood to a certain farni!y or farni!ies. Conse-

quently, it is advisable to record the family as a feature. For the family name it is not criticalwhat method of coding is employed so long as it is cleariy explained in notes acconlpanying thedatabase. Por instance, the family can he indicated as 3-1etter acron yms (Weber 1982) or as

numerical codes (see pp. 127 and 144-145 in Milier 1981).

234

IAWA Builetin lis., Vol. 10(3). 199 1 AWA List of microscopic fé-atures for hardwood identification 235

ANATOMICAL FEATURES

GROWTH RTNGS

1. Growth ring boundaries distinct2. Growth ring boundaries iridistinct or absent

Deflnitions:

Growth ring boundaries distinct = growth rings with an abrupt structural change at thcboundaries between them, usually including a change in fibre wall thickness and/or fibre radialdiameter, figs. 1, 2.

Growth ring boundaries indistinct or absent = growth rings vague and marked bymore or less gradual structural changes ai their poorly defined boundarics, or not visible, fig. 3.

Comments:Growth ring boundanes can be marked by one ar more of the following structural changes:

a. Thick-walled and radially llattened latewood fibres ar tracheids versus thin-walled early-wood fibres ar tracheids, fig. 1, e. g., Weinmannia trichosperma (Cunoriiaçeae), Laurus no-bílis (Lauraceae).

b. Marked differcnces in vesse] diarneter between latewood and earlywood of the followingring as in semi-riiig-porous and ring-parous woods, figs. 5-8, e.g., Juglans regia (Jug]an-daceae), Ulmus procera (til niaceae).

c. Marginal parenchyma (terminal or initial), fig. 2, e.g.,Xylopia nítida ( Annonaceae), Bra-chystegia Iauren:ii (Caesalpiniaceae), Juglans regia (Juglandaceae), Liriodendron tuliptfera(Magnoliaceae). lrregularly zonate, tangential parenchyma bands witfioui associated abrupichanges in fibre diameter or wall thickness are not considered marginal and do not represenidiscinct growth ring boundaries, e.g., Eschwei lera subglandulosa (Lecythidaceae), Irvingiaexcelsa (S imaroubaeeae).

d. Vascular tracheids and very narrow vessel elements very numerous or forming the groundtissue of the larewood, and absent from the earlywood, e.g., Sanbucus nigra (Caprifolia.ceae).

. Decreasing frequency of parenchynia bands towards the latewood resulting in distinct fibrezones, e. g.. Lecythis pisonis (Lecythidaceae), Doneila pruniformis (Sapotaceae).

t. Distended rays, e. g., Fagus spp. (Fagaceae).See Carlquist (1980, 1988) for other types of growth ring boundaries and for commonlyoccurring combinations of several of the above fearures.

.Although absence of growth ring boundaries is a clear enough descriptor, the differences be-en 'indistinct' and 'distinct' boundaries are somewhat arbitrary, and there are intermediates

:g. 4). Growth nngs may appear distinct when observed macroscopically, yet have indistinciboundaries ai the light microscopic leveI; distinctness of the ring boundaries should be judgedwith a microscope. Indistinct growth ring boundaries are very cornmon in tropical trees (fig. 3.

g., Spondias mombin - Anacardiaceae, Parkia nítida -- Min,osaceae, Coelocarvon preuasii\tvristicaceae; Xanrhophvllum philippinen.ve - Polygalaceae).

Nonperiodical, sporadic occurrence of ring boundaries (due to unusual clitnatic extrenies orniaic cvcrlts) should he recorded as rings ahsent or bouridaries indist inct.

Figs. 1 & 2. Growth ring boundaries distinct (feacure 1). - 1: Weinmunnia trichosperma, boun-dary niarked by differences in fibre and vessel diniensions, x 80. - 2: Xylopia nítida, boundaryrnarked by thick-wallcd latewood fibres and marginal parenchyma band, x 48. - Fig. 3.Growib ring boundaries indistinct or absent (feanire 2), Xanthophyllum philippinense x 22. -Fig. 4. Growch ring boundaries intermediate between distinct and indisunct (features 1 and 2variable), Jacaranda copaia, x 48.

236

POROSITY

3. Wood ring-porous4. Wood semi-ring-porous5. Wood diffuse-porous

Definizions:

Wood ring-porous = wood in which the vesseis in the earlywood are distinctly largerthan those in the Iatewood of the prcvious and of the sarne growth ring, and foi-rn a well definedzone or ring, and in which there is an abrupt transition to the latewood of the sarne growth ring,fig. 5, e. g., Quercus robur (Fagaceae), Frw(nus exce(sjor (Oleaceae), Phellodendron a,nurense(Rutaceae), Buineija lanuginosa (Sapotaceae), Ul,nu.s americana (Ulmaceae).

Wood semi-ring-porous = 1) wood in which the vesseis in the earlywood are distinctlylarger than those in the Iatewood of the previous growth ring, but in which there is a gradualchange to narrower vesseis in Lhe intermediate and latewood of the sarne growth ring; or2) wood with a distinct ring of closely spaced earlywood vesscls that are not markedly largerthan the Iatewood vessels of the preceding ring or the sarne growth ring. Alternative definition:intermediate condition between ring-porous and diffuse-porous wood, figs. 6, 7, e.g., Cordiatrichozona (Boraginaceae), Juglans nigra (J ugi andaceae). Lagersrrocmia floribunda (Lythra-ceae), Cedrela odorara (Meliaceae), Prerocarpus indicas ( Papilionaceae), Prunus amygdalus(Rosaceae), Paulownja romentosa (Scrophujarjaceae)

Wood diffuse-porous = wood in which the vesseis have more or less the sarne diarneterthroughout the growth ring, figs. 9, 10, e. g., Acer spp. (Aceraceae), RJ2ododefldron wadanum(Encaceae), CercidipJiyllu,njapjcum (Cercidiphyllaceae), Swjetenia spp. (Meliaceac), Entero.lobium spp. (Mirnosaceae); the vast rnajority of tropical species and most temperate species.

Comments:

The three features for porosity form an intergrading continuum and many species range fromdiffuse-porous to semi-ring .porous, or from ring-porous to semi-ring-porous. Porosity (fea-iures 3-5) is coded independently of vessel arrangenient (features 6-8).This iniplies thatwoods with a distinct vessel arrangernent (features 6-8), as well as those with evenly dis-Uibuted vesseis, may be diffuse-porous.

In some temperate diffuse-porous woods (e- g, Pagas spp. —Fagaceae, Platanu.s spp. -Plalanaceae) the Iatest formed vesse]s in the latewood may be considerahly smaller than those ofthe earlywood of the next ring, but vessel diarneter is more or less uniforrn throughout rnost ofthe growth ring (fig. 10).

In a description, characteristjcs of the earlywood ring of ring-porous woods should benoted, i.e., describe how rnany vessels wide the ring is. Sudo's (1959) key used the features'pore ring: l-seriate' and 'pore ring: multiseriate'. Such characteristics can be useful in distin-guishing between species, e.g., Ulmus americana typically has an earlywood zone that is onevessel deep, Ulrnus rubra has ai earlywood zone that is more than two vesseis deep.

Caurion: Slow grown ring-porous woods have narrow growth rings with very little latewood(fig. 8). Be careful not to confuse the closely spaced earlywood zones of slow-grown ring-porous woods with a tangential partem, or to interprel such woods as diffuse-porous.

Fig. 5. Wood ring-porous (feature 3), Phellodendron amurense, x 28. - Figs. 6 & 7. Woodsemi-ring-poroti s (feature 4). —6: Prunus sp., x 25. - 7: Paulownia tomenzosa, x 18. - Fig. 8.Wood ring-porous (feature 3), bui with narrow rin gs givino false irnprcssion of di ffuc- nrsemi_nngporsj. Caralpa binon [odes. x 30.

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Figs. 9 & 10. Wood diffuse-porous (feature 5), - 9: Rhododendron wadanum, x 75. - 10:

Cercidiphyllwn japonicum, classified as diffusc-porous despite di fference s in vcssel diarneter ofIatest forrned latewood and earlywood. x 30.

VESSEL ARRANGEMENT

6. Vesseis in tangential bands7. Vesseis in diagonal and for radial pattern8. Vesseis in dendritic pattern

Definirions:

Vesseis in tangential bands = vesseis arranged perpendicular to the rays and forrning

shori or lon go tangential bands; these bands can be straight or wavy; includes ulrniforrn and fes-tooned, figs. 11-13, e.g., Kalopanax piclus (Araliaceae), Patagonulu americana (Boragina-

ceae), Enkianthus cornuus (Ericaceae), Madura pom (fera (Moraceae), Pirtosporusn tobira (Pino-

sporaceae), Cardwellia sublirnis (Proteaceae).

Vesseis in diagonal and/or radial pattern = vesseis arranged radialiy or intermediatebetween tangential and radial (i. e., oblique), figs. 14, 17, 20. e. g., Lithocarpus edulis (Faga-

ceae), Calophyllum brasiliense, C. papuanwn, Mesuaferrea (Guttiferae), Eucalyptus diversi-

colar, E. obliqua (Myrtaceae), Amyris sylvatica (Rutaceae), Chloraluma gonocarpa (Sapota-

ceae). Synonym for diagonal: in echelon'.

Vesseis in dendritic pattern = vesseis arranged in a branching patiem, forining distincttracEs, separated hy arcas devoid of vesseis, figs. 15, 16, e. g, Rhus aromarica (Anacardiaceae),

Castanea dentara (Fagaceae), Chionanihus retusus (Oleaceae), Rhamnu.s carhartica (Rhamna-

ceae), Bumelia lanuginosa (Sapotaceae). Synonym: ti ame-like.

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Figs. 11-13. Vesseis in tangential bands (feature 6). —11: Latewood vesseis in tangential bands(note aiso feature 3, wood ring-porous), Kalopanax picrus, x 80. - 12: Vesseis and parenchyma'festooned', Cardwellja sublimis, x 30, - 13: Ali vesseis in tangential bands, Enkianrhuscornuus, x 75. Fig. 14. Vessels in a diagonal patterri (feature 7), Calophyllum papuanuin,x 29.

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Figs. 15 & 16. Vesseis in a dendritic pattern (feature 8). - 15: Rhamnus cathartjca (note alsofeature 5, wood diffuse-porous), x 60. - 16: Rhus arornatica, clendritic pauern restrictcd toIatewood vesseis (note also feature 3, wood ring-porous), x 35. --- Fig. 17. Vessels ir] aradial pattern (feature 7), Amyris sy/vazica, x 18. - Fig. 19. Narrow vesseis in a tangential iodiagonal pattern (features 6 and 7), Kalopanax picrus (note also feature 3, wood ring-porous),x 80.

IAWA List of microscopic features for hardwood identification

Fig. 19. Vesseis in a diagonal to dcndritic pattcrn (fcatures 7 and 8), Burnelia ohwifo1ia (n(Itealso featiire 5, wood diífuse-porous), x 45. - Fig. 20. Vesseis in a diagonal tu radial pattcrn(feature 7), Lirhocarpus edulis, x 29.

Procedure:Vessel disnibution patterns (tangential, diagonal /radial, dendritic) are determined from the

cross section at a low magnilication, and are recorded only where there is a distinct pattern. Inring-porous woods, only the internied iate- wood and latewood are earnined. The ring ofvesselsat the beginning of lhe growth ring of ring-porous woods is not considered when determiningvessel distribtnion pattems.

Commenrs:These features often occur iri cornbination, Vesse] arrangement in some woods intergrades

between tangential and diagonal (fig. 18). Diagonal and dendriric oftcn iritergrade (fig. 19). AlIapplilable features shou]d be recorded.

The arrangement of pore clusters seen in most species of Ulmus (Ulmaceae) lias been calledulmiform; thjs describes woods where the latewood clusters are predorninantly in wavy tan-gential hands (feature 6) and sornetimes temi to a diagonal patern (feature 7). Tangential ares oívesseis, typical of the Proteaceae (fig. 12), have heen cal]ed festooned.

Since, in ring-porous temperate spccics, these patterns (features 6-8) may be resuicied tuthe latcwood, their expression depends on ring width, and when rings are narrow these patternsare not obvious.

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VESSEL GROUPINGS

9. Vessels exelusively solitary (90% or more)10. Vesseis in radial multiples of 4 or more common11. Vessel clusters common

DeJinitions:

Vessels exclusively solitary = 90% or more of the vessels are completcly surroundedby other elernents, i. e., 90% or more appear not to contact another vessei, as viewed in crosssection, fig. 21, e. g., Aspidosperina quebracho (Apocynaceae), Caraipa spp. (Bonnctiaceae),Eucalyptus regnans (Myrtaceae), Malus sylvestris (Rosaceae), Schirna wallichii (Theaceae).

Radial multiples o! 4 or more cornmon = radial files of 4 or more adjacent vesseis ofcommon occurrence, fig. 22, e.g., Cerberafloribunda (Apocynaceae), Ilex aquifõliwn (Aqui-foi iaceae), Brachylaena hutchin.sii (Compositae), Elaeocarpus hookerianus (Elaeocarpaceae),Strychnos nux-vomica (Loganiaceae), Arnyris balsamjfera (Rutaceae), Gambeya excelsa (Sapo-taceae).

Clusters common = groups of 3 or more vesseis having both radial and tangential con-tacts, and of common occurrence, fig. 23, e.g., Polyscias elegans (Araliaceae), Pirtosporurnferrugineum (Pittosporaceae), latewood of Glediisia triacanihos, Gymnocladus dioica (Caesai-piniaceae), Morus alba (Moraceae), and Ailanrhus altissima (Sirnaroubaceae).

Com.'nenzs.'Feature 10 'radial multiples of 4 or more common' should be used only when radial muitiples

of 4 or more are an obvious feature of the transverse section. Feature 11 'clusters common' ap-plies only when clusters are frequent enough that they are easily observed during a quick scan ofa cross section. Clusters and radial rnultiples of 4 or more are not rnutually exclusive and canoccur in combination. Woods with vesseis in tangential bands (feature 6) ofren have clusters.

The most common vessel grouping is radial multiples of 2 to 4 wirh a variable proportion ofsolitary vessels (fig. 24). The absence of features 9-11 automatically irnplies this condition,

When describing a wood, ao index of vessel grouping can be calcuiated in the manner re-comrnended by Carlquist (1988): count the total number of vesseis in a minimum of 25 vessel'groups' (i.e., count both solitary vesseis and vessel multiples as a 'group'), divide the totalnumber of vesseis by 25 (the number of groups counted). An index of 1.00 indicates exclusive-ly solitary vessels, and the higher the index, the greater the degree of vessel grouping.

Caution: Care is needed to recognise rhe foliowing as not being multiples: (i) solitary vesseis Fig. 21. Vesseis 'cxclusivcly solitary' (feature 9), Aspidosperrrza quebracho, x 45. - Fig. 22.composed of vessel elements with oblique overlapping end walis giving the appearance ofvessel Radial rnultiples of 4 or more cominon (feature 10), Elaeocurpus hookerianus, x 29. Fig. 23.pairs on the cross section as in Cercidiphyllurn (Cercidiphyllaceae) and Illicium (llhiciaceae), and Clusters common (feature 11), Gymnocladus dioica, latewood, x 140. - Fig. 24. Vesseis part-(ii) closely associated solitary vessels, as in some species of Eucalyptus (Myrtaceae) and Calo- ly solitary, partiy in radial multiples of 2-4, or very small c1usters (features 9, 10, and 11phyllurn (Guttiferae) (Brazier & Franklin 1961). absens), Drypetes gerrardii, x 75.

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IAWA Bu]letin os., Vol. 10 (3)1989 IAWA List of microscopic features for hardwood identification 245

SOL1TARY VESSEL OUTLINE

12. Solitary vessel outline angular

Definition.

Solitary vessel outline angular = shape oU so]iary vessel outline is angular as viewedin cross section, fig.25, e.g., Aexroxkonpuncratum (Aextoxicaceae), Cercidiphyllwnjaponi-cum (Cercidiphyllaceae). Iatewood vesseis of white oaks (e. g., Quercus alba, Q. robur—Faga-ceae), Stemonurus luzoniensis (Icacinaceae), Hortonia spp. and Mol1ini spp. (Monimiaceae).

Procedure:In ring-porous woods, examine the latewood because in these woods the earlywood vesseis

are almost always circular to oval in outlije. Use Lhe outline of the solitary vesseis because thecornrnon walis of vesseis in inultiples can be flattened giving pari oU the vesseis ao angular oul-une.

Cornmen:s:Absence of feature 12 implies chai Lhe vessel outlinc is circular to oval (fig. 26) as in Banara

regia (Flacourtiaceae) and the latcwood oU red oaks (e. g,, Que rcusfcdcara - Fagaceae).

Caution: For fossil or archaeological samples, use this tèature only when there obviously is nodistortion from shlinkagc or post-depositional events. Distortion and 'folding' ofthe rays mdi-cates that the wood has been compressed during burial and that vessel outline probably has heenaliered.

Fig. 25. Solitary vessel outline angular (feature 12), Stemonurus luzoniensis, x 75. -- Fig. 26.Outline of vessels rounded (feature 12 absent), Banara regia, x 45.

246 - IAWA Bulietin n.s, Vol. 10(3), 1989 1 AWA List of microscopic features for hardwood identification 247

PERFORATION PLATES

13. Siniple perforation plates14. Scalarifor'm perforation plates

15. Scalariform perforation plates with 10 bars16. Scalariform perforation plates with 10-20 bars17. Scalariform perforation plates with 20-40 bars18. Scalariform perforation plates with ^ 40 bars

19. Reticulate, forarninate, and/or other types of multiple perforation plates

Definizions:

Simple perforation plate = a perforation plate with a single circular or elliptical opening,Íg. 27, e. g., Aesculus hippocasranwn (Hippocastanaceae), Entandrophragrna spp. (Meliaceae),Prerocarpus spp. (Papilionaceae), Zellwva spp. (Ulmaceae).

Scalariform perforation plate = a perforation plate with elongated and parailel openingsseparated by one to many mainly unbranched bars, lig. 29, examples follow.

Scalariforrn perforation plates with :^ 10 bars, e. g., Corytus aveilana (Corylaceae),Goupia spp. (Goupiaccae), Liriodendron tulipifera (Magnoliaccae), Coula edulis (Olacaceae),Rhizophora mangle (Rhizophoraceae).

Scalariform perforation plates with 10-20 bars, e.g., Betula verrucosa (Betula-ceae), Altingia excelsa, Liquida,nbar styracflua (Harnamelidaceae), Saco glortis gabonensis (1 lu-miriaceae), Schi,na wallichii (Theaceae).

Scalariform perforation plates with 20-40 bars, fig.29, e.g.,Cercidiphyllum japo-nicum (Cercidiphyllaceae), Dicoryphe sripulacea (l-Iamamelidaceae), Nyssa ogeche (Nyssaceae),Staphylea pinn.ara (Staphyleaceae).

Scalariform perforation plates with ^ 40 bars, e.g., Aexroxicon puncrazum (Aex-toxicaceae), Hedyosmwn spp. (Chloranth aceae), Dillenia iriquerra (Dileniaceae).

Reticuate perforation plate = a plate with closely spaced openings separated hy wallportions that are much narrower than the spaces between them, or with a profuse and irregularbranching of wall portions resulting in a netlike appearance, fig. 30, e. g., Didymopanax moro-toroni (Araliaceae), Iryant hera juruensis (Myristicaceae).

Forarninate perforation plate = a plate with circulas or elliptical openings like a sieve:the rernaining wall portions can be thicker than ín the reticulate type, fig. 3 1, e. g., Oroxylumindicum (Bignoniaceae).

Other types = for instance, complex or radiate perforation plates, see comments and figs.32-35.

Co,nments:Determine the type(s) of perforation plate fron radial sections or maccrations, preferahly

examine at least 25 vessel elements. For scalariform perforation plates, record ali the fcaturecategories thar encompass the range of the number of bars. Feature 14 'scalariforrn perforationplates' is a general category included to accommodate infortnation from cxisting literature thatindicates whether scalariform perforation platcs are prescnt, but not the number of bars. Feature14 is to be recorded wi th other appropriate features for bar number (15 –18).

Fig. 27. Simple perforation plates (fcature 13), Aesculus hippocastanum, x 105. - Fig. 28.Simple perforation plate and scala.riform perforation plate with 2 bars (features 13, 14, 15),Didynopanax morotoronj, x 115. - Fig. 29. Scalariforrn perforation plate with 20-40 bars(features 14 and 17), Staphylea pinnata, x 220.— Fig. 30. Reticulate perforation plate (feature19), Didymopanax ,norototonj x 115. - Fig. 31. Foraminate perforation platc (feature 19),Oro'.hvn indu ,iun, 115.

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248 - IAWA Bulletin n.s., Vol. 10 (3), 1989 IÁWA LisL of inicroscopie features for hardwood idenLification 249

Fig. 32. Perforation plate obliquely compound scalariforrn with anasiornosing bars (features 14and 19), Jryanthera paraensis, x 290. Fig. 33. Perforation plate regularly reticulate (feature19, often occurring together with feature 14, scalariform perforarion p]ates), Iryantherajuru-ensLs, x 290. - Fig. 34. Perforation plate cornpiex scalariforni and reticu]ale (features 14 and19), Iryanthera elliptica, x 290, - Fig. 35. Radiate perforation piatc (feature 19), Cyrharexyiwnmyrianrhum, x 300 (SEM).

Simple perforations are the most common Lype of perforation plate, and occur in over 80% ofthe world's woods (Wheeler et ai. 1986). Most woods have exclusively sirnple perforations,some have simple perforations together with scalariforin and/or other types of multiple perfora-tiori plates, and still others have exclusively scaiariform perforalion plates. When more tban onetype of perforation plate is present (fig. 28), ai] types should be recorded and may be uscd toidentify ao unknown (e.g., Didymopanax mororotoni— Araiiaceae, Oxydendron arboreum-Ericaceae, Fa,us sylvatica - Fagaceae, and Piaranus occidenralis - Platanaceae have both sim-pie and scalariform plates). In those woods with both simple and scalariforrn perforalion plates,the narrower vessel elcmcnts and the latewood vessel elements are more likely to have scalari-form perforatioii piares.

Scalariforrn, reticulate, and foraminate piares forni a continuum, and the larter mo are oftenconfused in the literature. Reticuiate and forarninate plates are restricted to re]ative]y íew taxon-oniic groups and are cornbined here. Reticulate perforations frequent]y occur itt combinatioriwith scalariform piares and are an elaboration of that type. !ryanthera (Myristicaceae), Dendro-panax and Didymopanax (Araliaceae) have scaiariforrn, reticulate, and varied intermediates plussimpie perforations; Myrceugenia estreilensis (Myrtaceae) has simple and niuldplc plates and thelarter can be variousiy described as irregular-scaiariforni, forarninate, or even reticulate; Mark-hainia and Oro.xylu.rn (Bignoniaceae) have simple and foraminate platcs.

!ryanthera (Myristicaceae) also lias cornpound scaiariform piares with few coarse bars withscts of fine secondary bars hetween them, which are often branchcd. Similar examples occur inDidymopanax marototoni (Araliaceae) and Ternsrroemia serram Theaceae). In these cases, botlifeature 14 (scalariform perforation piares present) and feature 19 appiy. As pointed out by Cari-quist (1988), the temi 'ephedroid' shouid not be used for foraminate perforations in dicotyle-dons,

Radiate perforation piates (alto feature 19) with a central wall and radiating simp]e andbranched bars extending to the lateral vessel wall are found in Cyiharexylurn myrianthwn (Ver-benaceae) (Vidal Gomes ex ai, 1989) and Caryocar microcarpum (Caryocaraceae).

Other types of multiple perforations may be found in the future and should be recorded asfeature 19, 'reticulate, forarninate, and/or other types of rnultiple perforations'.

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250 - IAWA Bulietin n. s., Vol. 10 (3), 1989

INTERVESSEL PITS: ARRANGEMENT AND SIZE

20. Intervessel pits scalariform21. Intervessel pits opposite22. Intervessel pits alternate

23. Shape of alternate pits polygonal

Intervessel pit size (alternate and opposite)24. Minute - ^ 4 im25. Small — 4-7 im26. Medium - 7-10 im27. Large - ^ 10 im

28. Range of intervessel pit size (J.Lm)

Definitions:

Intervessel pits = piLs between vessel elements.Scalariform intervessel pus = elongated or linear intervessel pits arrange.d in a ladder-

like series, fig. 36, e.g., Dillenia reiiculara (Dilleniaceae), Michelia compressa (Magnoliaceae),Laurelia spp. (Monirniaceae), R/zizophora spp. (Rhizophoraceae).

Opposite intervessel pits = intervessel pits arranged in short to long horizontal rows,i. c., rows orientated transversely across the Iength of the vessel, figa. 37, 44, C. g- Lirioden-dron spp. (Magnoliaceae), Nyssa ogeche (Nyssaceae).

Alternate intervessel pits = intervessel pits arranged in diagonal rows, figs. 39, 40, 42,43, e. g., Aceraceae, Mappia racemosa (Icacinaceae), Leguininosae, Mel iaceae, Salix spp. (Sali-caceae), Sapindaceae,

Shape of alternate pits polygonal = outline of intei-vessel pits, as seen in surface view(longitudinal sections), angular and with more than 4 sides, fig.40, e. g., Salicaceae, most Legu-minosae.

[ntervessel p11 sim (alternate and opposite) = horizontal diameter of a pit chamber atthe broadest point

Procedure:Generaily, surface views of intervessel pits are easiest to find in tangential sections because

radial multiples are the most frequent type of vessel multiple, and so intervessei pits are rnostfrequent in tangenlial walis. When vesseis are in tangential bands and/or clusters, radial sec-tions also provide surface views of intervessel pits. In woods with (almost) exelusively solitaryvesseis, intervessel pits will be extimely rare, and often not visible in a single longitudinal

Fig. 36 Intervessel pits scalariform (feature 20), Michelia compressa, x 115. - Fig. 37. Inter-vessel pits opposite (feature 21), Liriodendron tulipifera, x 115. — Fig 38. Intervessel pits sca-lariform to opposite (features 20 and 21), Ilex laurina, x 350. --- Fig. 39. Intervessel pitsalternate (feature 22), Mappia racernosa, x 112. — Fig. 40. Shape of alternate pits polygonal(feature 23), Salix sp. Note also features 22 (pits alternate) and 26, 27 (intervessel pits mediumto large); x 290. — Fig. 41. Shape of intervessel pits circular t o oval (feature 23 absent). Notealso plIs opposite (feature 21), Nothofagus moorei, x 300. — Fig. 42. Intervessel pits minute,less rhan 4 p.m (feature 24), Polyalthia oblongifolia. Note also pits alternate (feature 22), x 300.— Fig. 43. Vesturesl intervessel pits (feature 29), Terminalia sp., x 825. — Fig. 44. Pits seern-ingly vestured due to presence of soluble deposits (feature 29, vestured pits, ahsent). Note alsopits opposite (feature 21). Ilex cyniosa, x 800.

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252 tAWA Builetin ns., Vol. 10 (3), 1989 IAWA List of microscopic features for hardwood identification - 253

section. In such woods, intervessel pit shape and size must be observed in overlapping end wallportions of vessel elements in a single vessel. However, in woods with vessel multiples, lhe pitarrangemcnt, shape, and size is best determined frorn lhe middle of lhe larger vessel clements.Measure ten pits, avoiding exceptionally large or small pits, and record those size classes thatencompass lhe range ofpit size.

Comments:Alternate intervessel pitting is lhe most common, and opposite and scalariform intervessel

pitting are found in relatively few groups. When alternate pits are crowded lhe outlines of lhepits tend to be polygonal in surface view; if alternate pits are not crowded thcn lhe outlines areusually circular to oval. \Vhen opposite intervessel pits are crowded lhe outlines of lhe borderstend to be rectangular in surface view. Some spccies have both polygonal and circular to ovalintervessel pit outlines, record featurc 23 present for such woods. Combinations of differentpitting patterns and/or intergrad.ing types occur (e.g., figs. 38, 41, alternate and opposite inBuxus - Buxaceac, opposite and scalai-iform in Liquidam bar - Hamamelidaceae) and may beindicated by using combinations of Lhe different pit fcatures.

Pit size can help distinguish between genera within a family and between fainilies, e. g_many Meliaceae have minute pits, while many members of the Anacardiaceae have large pits.The most widely used convention for determining pit size is to measure horizontal pit diame ter.To enable use of existing data this pararneter is included in this feature list. However, withinseveral taxa, particularly those with some or ali opposite to scalaiiform pits, vertical diameter is amore constant and diagnostic feature, and it is recommended that this dirnension be recorded in adescription.

Cauzion: Do n'oL mistake vessel-vasiceniric tracheid pitting for intervessei pitting.

VESTURED PITS

29. Vesturcd pits

Definition:

Vestured pits = pits with lhe pit cavity and/or aperture wholl y or partly lined with pro-jections from lhe secondary ccli wall, fig. 43, e. g., Comhretaceae, Lythraceae, Myrtaceae,Rubiaceae, most Legurninosae.

Procedure:Vestures are best viewed in water or glycerin mounts (or SEM). Bleaching is recornmended

50 as to remove encrusting materiais that nlay be mistaken for vestures (fig. 44 shows pseudo-vestures), i.e., soak sections (or, for SEM observation, wood blocks) in any household bleachuntil Lhe section or surface has lost its colour, rinse in water, and finish saniple preparation.

Comments:Vesturing may occur in intervessel, vessel-ray or vessei-axial parenchyma, intertracheid, or

interfibre pits.Vestures generaily are characteristic of entire farnilies, or groups within a famiiy. The num-

ber, size, and distribution of vestures varies considerably and these variations may be of diag-nosuc value (Baiiey 1933; Ohtani eral. 1984; Van Vliet 1978; Van Vliet & Baas 1984). Whenintervessel pits are large and Lhe vestures are coarse (e. g., Terminalia spp. - Combretaceae),vestures are relatively easy to see with an oii-immersion objective of a good compound micro-scope. But when lhe vestured pits are minute (4 irn or less) as in lhe Apocynaceae or Rubiaceae,lhe vestures are difficuit to see with a compound microscope, and only clearly visible with ascanning electron microscope.

VESSEL-RAY PITFING

30. Vessel-ray pits with distinct borders; similar to intervessel pits in size andshape throughout the ray ceil

31. Vessel-ray pits with much reduced borders to apparently simple:pits rounded or angular

32. Vessel-ray pits with rnuch reduced borders to apparently simple:pits horizontal (scalariform, gash .like) to vertical (palisade)

33. Vessel-ray pits of two distinct sizes or types in the sarne ray celI

34. Vessel-ray pits unilaterally compound and coarse (over 10 jm)

35. Vessel-ray pits restricted to marginal rows

Dejlnitions:

Vessel-ray pits = pits between a ray celi and a vessel eicmcnt.

linilaterally compound pita = pits in which one pil abuts two or more smalier pits in theadjacent celi.

Other features as per descriptors, examples follow.

Vessel-ray pits with distinct borders; similar to intervessel pts in size andshape throughout the ray cell, figs. 45, 46, e.g., Aceraceae, Leguminosae, Meliaceae,Jiex aquifoliwn (Aquifoliaceae), Betula spp. (Betulaceae), Camprostemon philippinense (Bom-bacaceae), Couratari cf. oblongifolia (Lecythidaceae).

Vessel-ray pita with much reduced borders to apparently simple: pita round-ed or angular, figs. 47, 48, e. g., Elaeocarpus calomala (Elaeocarpaceae), Clinostemon spp.(Lauraceae), Eucalyptus spp. (Myrtaceae). Popular spp., Salix spp. (Salicaceae).

Vessel-ray pits with much reduced borders to apparently simple: pits hori-zontal (scalariform, gash-like) to vertical (palisade), figs.49, 50, e.g., Trigonobala-nus vertici/lata, Quercus spp. (Fagaccae), Atherosperma moschata, Laurelia aromatica (Moni-miaceae), HorsJieldia subglahosa (Myristicaceae), Syzygiwn spp. (Myrtaceae).

Vessel-ray pita of two distinct sizes or types in the sarne ray cell, figs. 51, 52,e.g., some species of Erythroxylum (Erythroxyiaceae), Anacolosa spp., Chaunochiton spp.(Olacaceae), Santa/um spp. (Santalaceae), Planchoneila spp. (Sapotaceae).

Vessel-ray pits unilaterally compound and coarse (over 10 Lm), fig. 53, e.g.,Michelia champaca (Magnoliaceae), Ceriops spp., Kandelia spp., Rhizophora spp. (Rhizopho-raceae).

Vessel-ray pits restricted to marginal rows, fig. 47, e. g., Carpinus bezulus (Co-rylaceae), Aesculus hippocasranum (Hippocastanaceae), Populus spp., Salix spp. (Salicaceae).

Comrnenrs:Vai-ious combinations of lhe above features may occur and should be recorded. Vessei-ray

pits in lhe body of lhe ray may differ from those in lhe ray margins (e. g., Pala quium gaiato-xylum - Sapotaceae). Record lhe features for both types of pits.

lia wood has predoniinantly solitary vesseis, comparison of vessel-ray pits with intervesselpita often is not possibie. li lhe vessei-ray parenchyma pits in such woods are uniform in sizeand shape and have borders, then use feature 30; ifnot, any of features 31-35 may apply.

Vessel-axial parenchyma pitting usually resembles vessel-ray parenchyrna pitting, and istherefore not inciuded as a separate iist of alrnost identical descriptors.

254 IAWA l3ulletin n.s., Vol. 10 (3), 1989

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Figs. 45 & 46. Vessel—ray pits with distinct borders, similar to intervessel pits (feature 30). -45: Courazari cf. obIongfolla, x 290. - 46: Carnpwste,non philippinense, x 75. Figs. 47 &48. Vessel—ray pits wir.h rnuch reduced borders to apparently simple, pit outline rounded (feature31), —47: Salix sp. (Salicaccae). Note also feature 35 (vessel—ray pits restrictcd to marginalrows); x 290. - 48: Elaeocarpus calornala, x 290. - Figs. 49 & 50. Vessel-ray pits with rnuchreduced borders co apparently simp]e, pits horizontal (gash-Iikc) to vertical (palisade), fc.ature32. - 49: Pits horizontal, Atherosperrna ,noschata, x 450. - 50: Pics vertical, Trigonobalanusverticillara, x 290. - Fig. 51. Part of the vessel-ray pits with much reduced borders, and pits ofIwo distinct sizes or types in the sarne ray ccli (features 32 and 33), I-Iorsfieldia suhglobosa,x 115.

IAWA List of niicroscopic features for hardwood identification

255

Fig. 52. Vesscl—ray pits of two distinct sizos or types iii the sarne ray ce.l1 (feature 33); thc largepits (arrowcd) resembie perforations, Chaunochiton brevifloruin, x 290. - Fig. 53. Vessel—raypits uni]aterally compound and coarse (feature 34), Ceriops raa1 (differentiai interference con-trast), x .450,

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256

IAWA Builetin n.s., Vol. 10 (3), 1989 IAWA List of rnicroscopic features for hardwood identification

257

HELICAL THICKENINGS

36. Helical thickenings in vessei elements present37. Hetical thickenings throughout body of vessel element38. Helical thickenings only in vessel element tails39. Hetical thickenings only in narrower vessel elements

Definitions:

Helical thickenings in vessel etements = ridges on the inner face of the vessel elemeniwall in a roughly helical pattern. Synonym: spiral thickenings.

Other features as per descriptors, exarnples follow.

Helical thickenings throughout body of vessel etement, figs. 54, 55, e.g., Acerspp. (Aceraceae), Aesculus spp. (Hippocastanaceae), Cyrisus scoparius (Papilionaceae), Prunusspinosa (Rosaceae), Tilia spp. (Tiliaceae).

Helical thickenings onty in vessel element tails, figs. 56, 57, e. g., Cercidiphyllumjaponicwn (Cercidiphyllaceae), Liquidambar styraczflua (Hamamelidaceae).

Helical thickenings only in narrower vessel elements, e.g., Robinia pseudoacacia(Papilionaceae), Ulmus americana (Ulmaeeae).

Commenrs:Helicai thckenings are rather variable in terms of thickness (fine to coarse), inclination angle

(nearly horizontal to steeply inclined), branching (branched or unbranched), and spacing (doseto wide). li is recomxnended that observations on these features be included in wood descrip-tions.

Feature 36 'helical thickenings in vessel elements' is included as a general category to 1) ad-commodate information frorn existing databases that indicate whether helical thickenings arepresent, but not their specific location; and 2) to help with the identification of small wood frag-ments in which vessel elements have helical thickenings, but because of the small sample size itcannot be determined whether Lhe helical thickenings are in ali vessel elements, or just in Lhenarrower ones. Feature 36 should be recorded in combination with other appropriate features(features 37, 38 or 39) for helical thickenings.

Helical thickenings can also occur in vascular! vasicentric tracheids, and in ground tissuefibres (feature 64), and very rarely in axial parenchyma.

Caution: Do not confuse coalescent pit apertures with helicai thickenings.

Figs. 54 & 55. Helical thickenings throughout body of vessel elernent (features 36 and 37). -54: Prunus spinosa, x 290. - 55: cyrisus scoparius, x 220. Figs. 56 & 57. Helical thicken-ings only in vessel elemeni tails (features 36 and 31), Cercidiphvllurn japonicuin. - 56: x 150. -57: x 240.

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IAWA Bulietin n.s., Vol. 10 (3), 1989

IAWA List of microscopic features for hardwood identification

259

TANGENTIAL DIAMETER OF VESSEL LUMINA

Mean tangential diameter of vessel lumina40. ^ 50 jim41. 50-100 gm42. 100-200 im43. ^- 200 tm

44. Mean, +I . Standard Deviation, Range, n =

Procedure:Vessel diameter is measured in transverse sections. Vesseis are selectcd for measurement

with care not to bias the selection towards the larger or smaller vesseis. The rangential diameterof the vessei luniina, excluding the wali, is measured at the widest part of Lhe opening. At least25 vesseis should be measured. Ining-porous woods (feature 3) and woods with 'vcssels oftwo distinct diameter classes, wood not ring-porous' (feature 45), only measure and record thelarger size class. Information about tangential diameters of the smailer vesseis wouid be usefulin a description. In semi-ring-porous woods, measure along a radial transect through a growthring. For semi-ring-porous woods, it is recommended that more than 25 vessels be measured;a larger standard dcviation is expected for such woods. Use the category(ies) in which themean(s) fali(s).

Comments:In trees, mean tangential diameters of 100-200 im are more cornrnon than mean tangential

diarneters greater than 200 im or mean tangential diameters less than 50 J.inl. In shrubs, meantangential diameters of less than 50 jim are conimon.

45. Vesseis of two distinet diameter classes, wood not ring-porous

Definirion:

Vesseis of two distinct diameter classes, wood not ring.porous woods with abimodal distribution of tangential diameters of vessel lurnina, fig. 58, e. g., Actinidia spp. (Acli-nidiaceae), Capparis maroniensis (Capparidaceae), Derris hylobia Papilionaceae), Serjaniasubdenrata (Sapindaceae), Congea ro,nenrosa (Verbenaceae).

Comrnen ts:Vines and xerophytes often have vesseis of two distinet diameter classes (Carlquist 1985;

Baas & Schweingruber 1987).

56. Tyloses common57. Tyloses sclerotic

Definitions:

VESSELS PER SQUARE MILLIMETRE

46. !^ 5 vessels per square millimetre47. 5-20 vesseis per square miltimetre48. 20-40 vesseis per square millimetre49. 40-100 vesseis per square millimetre50. ^ 100 vessels per square millimetre51. Mean, +I Standard Deviation, Range, n = x

Procedure:Ali vcssels are counted as individuais, e. g., a radial multiple of four would be counted as

four vesseis (Wheeler 1986). Count ali the vesseis in at least tive (and preferably ten) fields ofappropriate size (depending on vessel diameter and distribution), and convert to number persquare rniliimetre, i. e., for woods with small diameter vessels use fields 1 mm x 1 mm or iess;for woods with large vesseis that are widely spaced use whole fields of view at low magnifica.tion (e. g., 4 x objective lens). Of the vesseis that are partially in Lhe field of view, only 50% areincluded in the count. If vessei frequency is very low, examine enough fields to account forlocal variations, and preferably count at least 100 vesseis. Use the categories that include thetotal range of vessel frequency.

Cornmenrs:Vessel frequency is not computed for ring-porous woods, or for woods with their vesseis ia

definite tracts with vascular/vasicentric tracheids, e. g., dendritic pattern as seen in Rhamnu.scathartica (Rhamnaceae), or tangential bands as seen in Ulmus (Ulmaceae).

MEAN VESSEL ELEMENT LENGTH

52. ^ 350 l.m53. 350-80054. ^ 800 im55. Mean, +1— Standard i)eviation, Range, n = x

Procedure:Measure the whole iength of each vessel element from one tail end to thc other, preferably in

a maceration. AL least 25 vessel element lengths are measured to derive the mean and range. Usethe categoly(ies) in which the mean(s) fali(s).

TYLOSES ANO DEPOSITS IN VESSELS

Tyloses common = outgrowths from an adjacent ray or axial parenchyma ccli through a pitin a vessel wall, partially or completely blocking the vessel lumen, and ofcQmmon OccUlTence

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260 - - IAWA Builetin ns, Vol, 10 (3), 1989 IAWA List of rnicroscopic features for hardwood identification -- - -- 261

(except in outer sapwood), figs. 59, 60, e. g_, Anacardium occidentalis (Anacardiaceae), Acan-rhopanax spp. (Araliaceae), Cercidiphyllum japonicum (CercidiphyUaceae), Eucalyptus acme-niaides (Myrtaceae), Sti-ombosia pustulata (Oiacaceae), Robinia pseudoacacia (Papiionaceae).

Selerotie tyloses = tyloses with very thick, multilayered, lignified walis, figs. 61, 62,e, g., Chaetocarpus schoni burgki anus, Micrandra spruceana (Euphorbiaceae), Cantleya cornicu-lata (Icacinaceae), Eusideroxylon zwageri (Lauraceae). Brosimum guianense (Moraceae).

Procedure:In ring-porous woods, it is best to examine the earlywood vesseis for tyloses because ty10es

are often absent froni small diarneter latewood vesseis. Avoid sapwood when determining thepresence of tyloses or gums.

Commenrs:Tyloses may be few or many, ranging from ali vesseis fihled with many tyloses to a few ves-

seis with a few tyloses. Feature 56 applies only when tyloses are not of sporadic occurrence.Tyloses may be thin-walled or thick-walled, pitted or unpitte, with or without starch, crystals,resins, gums, etc. Such information should be recorded in a description.

Woods with selerotie tyloses usually have thin-walled tyloses as well, and both features 56and 57 tnay apply Some woods may have both tyloses and guni deposits (feature 58), and bothfeatures 56 and 58 may apply.

Caution: Absence af tylases is not diagnostic Do um code lraumatic tyloses such as occur inwound heartwood and be careful rim to confuse tyloses with foamy deposits, masses of fungi,ar other deposits.

58. Gums and other deposits in henrtwood vesseis

Cornments:In cross sections, deposits appear to completely fihi some vessel lumina (fig. 63); in longitu-

dinal sections, deposits often appear to collect at the end of vessei elements. Deposits often canbe seen more clearly by exarnining the woods with a hand lens; sectioning and rnounting tech-fiques may remove some of the deposits.

'Gums and other deposits' includes a wide variety of chemical compounds, which are vari-ously coloured (white, ye]iow, red, brown, black). Ia a description it is appropriate to indicatetheir abundance and colour. See Hillis (1987) for more informadon on the chemistry of depo-sits.

Cautíon: Use feature 58 positively oniy. Do not confuse masses of whitish fungi, which ma y bepacked in a vessel cavity, ar sclerotic tyloses with deposits.

Fig. 58. Vesseis of two disdnct diameter classes, wood not ring-porous (feature 45), Serjaniasubdentata, x 35, - Figs, 59 & 60. Tyloses common (feature 56). – 59: In transverse section,Anacardiurn occidentalts, x 220. - 60: Ia tangential secdon, Robinia pseudoacacia, x 140. —Figs. 61 & 62. Tyloses sclerotic (features 56 and 57), Cantleya corniculata. – 61: Transversescction, x 75. – 62: Tangential section, x 75. — Fig. 63. Gums/dcposits in heartwood vesseis(feature 58), Physocalymma scaberrimum, x 110.

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IAWA Bulietin n.s., Vol. 10 (3), 1989

WOOD VESSELLESS

59. Wood vesselless

Definition:

Wood vesselless = wood without vessel elements, cornposed only of imperforate trache-ary elements and parenchyma, figs. 64, 65, e. g., Amborellaceae, Tetracentraceae, Trochoden-draceae, Winteraceae.

Comnients:Vesselless dicotyledonous woods are relatively uncornmon and are distinguished from conif-

erous wood by tall multiseriate rays. For vesselless woods, it is not necessary to cocle for typeof imperforate tracheary elements (fibres or vascular/vasicentric tracheids) and impossible tocode for vessel features.

TRACHEIDS AND FIBEES

60. Vascular/vasicentric tracheids present

Deflnitions,

Vascular tracheids = imperforate edis resembling in size, shape, pitting, and wall orna-mentation narrow vessel elements and intergrading with the lattcr, figs. 66, 67, e.g., Sambuctisnigra (Caprifoliaceae), Sop hora arizonica (Papiionaceae), Phellodendron amuren.se (Rutaceae),Lycium europaewn (So!anaceae), Celtis occidenralis (Ulinaceae).

Vasicentric tracheids = imperforate celis with numerous distinctly bordered pits in theirradial and tangenhial walis, preserir around the vesseis, and different from ground tissue fibres,often, but not always of irregular shape, fig. 68, e. g., Castanea spp., Quercus spp. (Fagaceae),rnany Shorea (Dipterocarpaceae) and Eucalyprus (Myrtaceae) species.

Comments:Vascular tracheids often occur in association with extensive vessel rnultiples or clusters,

especially in the latewood. A very thorough search of macerations will reveal their presence iritnany species. 1-lowever, for wood identification purposes use rhein only when they are com-monly present. The intergradation of vascular tracheids with narrow vessel elements implies tharthere are some celis with a single, often very small, perforation. Some anatomists would preferto cail such edis vascular tracheids, others would prefer to cail them narrow vessel elements,probably terminating a ves.sel. Because they have a perforation such cells are best referred to asvessei elements; tracheids are imperforare edis.

The IAWA Glossary (1964) includes shortness and irregular form in the definition of vasi-centric tracheids, but these criteria do nor always apply (e.g., iii Eucalyptus spp., cf. lhe 1987).Since vascular tracheids are often intermixed with vessels (i.e., in a vasicentric position) inmany taxa, they can also be considered as vasicentric iracheids.

IAWA List of microscopie features for hardwood identification

263

Figs. 64 & 65. Wood vesselless (feature 59), Trochodendron aralioides. - 64: Transversesection, x 38. - 65: Tangential section, x 38. - Figs. 66-68. Vascular/vasicentnc tracheids(feature 60). 66: Radial section, vessei elements surrounded by vascular tracheids (note alsohelicai thickenings in vessel elements, features 36 and 37), Phellodendron a.'nurense, x 290, -67: Maceration, vessel element flanked by two vascular tracheids, Celtis occidentalis, x 300. -68: Radial section, vasicentric tracheids, Castanea sariva, x 170.

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264

IAWA Builetin n.s., Vol. 10 (3), 1989

IAWAList of microscopic features for hardwood identification

265

GROUND TISSUE FIBRES

61. Fibres with simple to minutely bordered pits62. Fibres with distinctly bordered pits63. Fibre pits common in both radial and tangential walis

Defini rions:

Fibres with simple to minutely bordered pits = fibres (libriform fibres) with simplepits or bordered pits with the chambers less than 3 tm in diameter, flgs. 71, 72, e. g., Swieteniaspp. (Meliaceac), Inga spp. (Mimosaceae), Fraxinus spp. (Oleaceae), Populus spp. (Salicaceae).

Fibres with distinctly bordered pits = fibres (or fibre-tracheids or ground tissue isa-cheids) with bordered pits with chambers over 3 p.m in diameter, figs. 69, 70, e.g., 1/ex spp.(Aquifoliaceae), Dilienia spp. (Dileniaceae), Illiciu.m spp. (llliciaceae), Xanrhophyllum spp.(Polygalaceae), Carneilia spp. (Theaceae).

Fibre pits common in both radial and tangential walis = fibre pits, either borderedor simple, common in radial and tangential walis, e. g., [lex spp. (Aquifoliaceae), Dilienia spp.(Dilleniaceae), 11/id um spp. (Illiciaceae), Xanthophyllum spp. (Polygalaceae), Clematis vitalba(Ranunculaceac), Carne/lia spp. (Theaceae).

Procedure:Determine the nature and distribution of fibre pits only in longitudinal (radial and tangential)

sections, because in cross section many fibre walis are not strictly radial or tangendal. Both lon-gitudinal and cross sections are suitable to determine if the pits are bordered or (almost) simple.

Commen:s:The feature 'fibres with distinctly bordered pits' partly overlaps with the descriptors 'tracheids'

sensu Bailey (1936) and Carlquist (1986a, 1986b, 1988) and 'fibre-tracheids' sensu Baas(1986). It usually coincides with 'fibre pits common in both radial and tangential walis' (feature63).

The following combinations are of very sporadic occurrence: 1) fibre pits not distinctly bor-dered, ie., pit chambers less than 3 j.un or pits simple, feature 61 present, and pits comrnon inradial and tangential walls, feature 63 present, e. g, Capparis spinosa (Capparidaceae), Nyctan-thes arbor-tristis (Oleaceae), Vitis vin(fera (Vitaceae); 2) fibres with distinctly bordered pits, fea-ture 62 present, and pits mainly restricted to the radial walis, feature 63 absent, e. g.. Elaeagnu.sangu.safolia (Elaeagnaceae).

Two types of fibres with respect to wall pitting (both features 61 and 62 present) may occur(e. g, some species of Vaccinium - Ericaceae).

Fibres with simple to minutely bordered pits (feature 61 present), mainly confined to theradial walis (feature 63 absent) are libriform fibres in the deflnition of Baas (1986) or libriformfibras and/or fibre-tracheids in the deflniuon ofCarlquist (1986a, 1986b, 1988).

The terms libriform fibras, fibre-tracheids, and 'true tracheids' have been deliberately avoid-cd as descriptors in this list because there is no consensus on their deflnitions.

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Figs. 69 & 70. Fibres with distinctly bordered pits (feature 62), common in both radial and t:m-gential walls (feature 63), tangential sections. - 69: lilicium carnbodianu,n, x 230. - 70: Xant/iphyllurn lanceatu,n, x 230. - Fig. 71. Fibrcs with simple to minutely bordered pOs (feature61), tangential section, phase-contrast, Populus sp. (Salicaceae). Note also .scarcity ofpits intangential walis (feature 63 ahsent); x 410. Fig. 72. Fibrcs with simple to minutely borderedpOs (feature 61), common in both radial and tangcntial walis (feature 63). Tangential seclion,phase-contrast, Clernatis viralba, x 410. - Figs. 73 & 74. Helical thickcnings iii ground tisuefibres (fet:re 64). - 73: 1/ex cjnerea. x 850. 74: JIe.ï chinensis, x 850.

266

IAWA Balietin n.s., Vol, 10 (3), 1989

64. Helical thickenings in ground tissue fibres

Definition.-

Helical thickenings in ground tissue fibres = as per feature descriptor, see definitionof helical thickenings, feature 36, tigs. 73, 74, e.g., Euonynus europaeus (Celasti-accae), Ha-name1isjaponica (1 larnamelidaceae), Cercocarpus ledifolius (Rosaceae), and tcmperate species

of 1/ex (Aquifoliaceae) and Syringa (Oleaceae).

Com ments.Fibres with helical thickenings usualty occur in woods that also have he]ical thickenings in

the vessel elements. However, the opposite is not true, Le., many species with helical thickcn-ings in their vessel elernents do not have helical thickeriings in the ground tissue fibres. Helicalthickenings are rnuch more cornmon iri fibres with distinctly bordered pits than in tibres withsinnple to rninutcly bordered pits. They also occur more frequently in tempera te woods thari intropical woods,

SEPTATE FIBRES AND PARENCHYMA-LIKE FIBRE BANDS

65. Septate fibres present66. Noriseptate libres present67. Parenchyma-Iike fibre bands alternating with ordinary tibres

Definitions:

Septate fibres = fibres with thin, unpitted, transverse wall(s), flgs. 75-78, e.g., Spondiasmombin (Anacardiaceae), A ucournea kíaineana (Burseraceae), Buchenaia capitara (Combreta-ccae), E!aeocarpus spp. (Elacocarpaceae), Aglaia spp. (Meiaeeae), Virex orinocensis (Verbena-ceae).

Nonseptate fibres = tibres without septa.

Parenchyma-like libre bands alternating with ordinary fibres = tangential bandsof relatively thin-walled fibres alternating with bands oí thicker-wallcd fibres, fig. 79, e. g.,Cassine spp., Mayxenus obtusifoila (Celastrace ae), Dubauria spp. (Compositac), Lagersiroemiatomernosa, Physocalymma spp. (Lythraceae), Cupania americana (Sapindaceae).

Com menu:Septa are formed after lhe secondary fibre waJls have been deposited; they therefore do not

extend to Lhe compound middle larnellae between adjacent fibres, Septa are usua]Iy unlignifiedand veiy thin (cf. Pararneswaran & Liese 1969).

In some woods, ali fibres are septate (feature 65 present, feature 66 absent), e.g., fig. 76,Lainea welwirschii, Spondias niombin (Anacardiaceae), Canariwn schwemnfiirthii (Bursera-ceae). In other woods, both septate and nonseptate flbres occur together (features 65 and 66boih present), eg., fig. 78, Buchenavia capirata (Conibretaceae), E/aro carpus spp. (Elaeocarpa-ceae), Swie:enia macrophylla (Meliaceae). The septate fibres rnay then either be scaitered irregu-Iarly, situated near the vesseis or the rays (feature 67 absent), or arranged in tangential bands(feature 67 presem).

1 AWA List of rnicroscopic features for hardwood identification

267

Figs 75-77. Septate fibres presem (feature 65). —75 & 76: Ali iibres septane, severa] septa perfibre, Aucouniea klaineana, - 75: x 290 —76: x 75 - 77: Many septa per fibre, Agia/a lirtora/is.x 150 Fig, 78. Septate (arrows) and nonseptate fibres presem iii lhe sarne sanipie (features65 and 66), Swietenja inacrophyIla, > 115. - Fig. 79L Parenchvtna-iike (ihi'e bands (feature67). Phys cah'nnma .scabcrrimu,n, x 45.

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Fig. 80. Fibre.s very thin-walled (feature 68), Neuburgia corynocarpa, x 290. - Fig. 81. Fibresthin- to thick-walled (feature 69), Michelia compressa, x 290. - Fig. 82. Fibres very thick-walled (feature 70), Rhizophora rnangle, x 290.

268 IAWA Butietin n.s., Vol. 10 (3), 1989

IAWA List of microscopic features for hardwood identification

269

The fibres of parenchyma-like fibre bands (featore 67) are usuaily septate; lhe ordinary fibresthey alternate with may be nonseptate (feature 66) as in Cassine maurocenia, Maytenus obru-

sifolia (Celastraceae), or septate as in Lagersrroernia tornentosa, Physocalymma scaberrimurn(Lythraceae). In lhe laner case, features 65 and 67 are presem, feature 66 is ahsent.

Fibre septation is coded independently of fibre wall pining (features 61-63).Thc number of septa per fibre can vary from 1 to many. This number can be taxon specific

(e.g., Van Vliet 1976b), and so lhe average number of septa per taxon shouid be given in adescription.

Caurions: Do not confuse tom ccli wali fragments, ceil wail deformations, gum deposits, fungalhyphac, or tyloses in fibres (seen in some Magnoiiaceae, Lauraceae) with septa. Sometimesparenchyma strands can also easily be confused with septate fibres.

Avoid tension wood, because gelatinous fibres are nonseptate.

FIBRE WALL THICKNESS

68. Fibres very thin-walled69. Fibres thin- to thick-walled70. Fibres very thick-walled

DeJinitions:

Fibres very thin-wailed = fibre lumina 3 or more times wider than lhe double wall thick-ness, fig. 80, e. g., in Bursera simaruba (Burseraceae), Te:ra,neles nudzflora (Datiscaceae),Neubergia corynocarpa (Loganiaceae), Ti/ia japonica (Tiliaceae).

Fibres Ihin- to thick-walled = fibre lumina less than 3 limes the double wall thickness,and distinctly open, fig. 81, e, g., in 1/ex spp. (Aquifoliaceae), Michelia compressa (Magnolia-ceae), Salix alba (Salicaceae).

Fibres very thick-walled = fibre lumina a]most compietcly closed, fig. 82, e.g., inGoupia glabra (Ceiastraceae), Lophira spp. (Ochnaceae), Strombosia pusxulwa (Olacaccac).Kr/4giodendronferreurn (Rhainnaceae), Rhizophora tnangle (Rhi zophoraceae).

Cauzions: In woods with distinct growth rings, fibre wail thickness changes throughout lhegrowth ring, and rnay be particularly thick aI lhe end of lhe growth ring. When describing fibrewali thickness, do ,tot consider these iast latewood fibres.

Also, do nol dcscribe gelatinous fibres (—tension wood fibres), which usual]y liave thickwalls with an unlignified gciatinous iayer,

MEAN FIE3RE LENGTI ISCommen:s:

Measurement of lhe actual thickness of fibre walls usually invoives an amount of work ou[ ofali proportion to lhe iimited diagnostic value of the figure obtained. Therefore, lhe classes forfibre wall thickness are based on lhe ratio of lumen to walt thickness (Chattaway 1932). Theratio proposed is that of lhe width of lhe lumen to lhe combined thickness of lhe walis between itand lhe lumen of lhe next ccli as viewed in cross section. When celis are flattened radiallv thelumen becomes oval and will give a different ratio with lhe wail according to whether it is meas-ured radiaily or tangentially; lhe radial measurement is suggested.

Chattaway (1932) proposed four categories; three are used here. Feature 68 roughiy corre-sponds to her category very thin'-walied; feature 69 includes her two categories 'thin' and'thick'; feature 70 is identical to her category 'very thick'.

Fibre wall thickness in many species is variable and there may be more than one category offibre wall thickness in a species.

71. 900 j.un72. 900-1600 j.irn73. ^ 1600 j.tm74. Mean, +I Standard Deviation, Range, n = x

Procedure:

Use macerations of mature trunk wood, and measure lhe length of at lcast 25 fibrcs to determine lhe mean, range, and standard deviation. Use lhe category(ies) in which lhe mear-i(s)fali(s). For woods with distinct growth rings, sample from lhe middie of lhe growth ring. Be-cause of lhe importance of ccli length in wood quality studies, a variety of rnethods have bccndeveloped to insure random selection of edis for measurement. It is recommended that one ofthese rncthods be used (Dodd 1986; Hart & Swindel 1967). There are very few woods in whichfibre len h :In Tnca1Ired acc uratclv from sccion s. so such a method n O rLc( ,rnrncndcd.

270 - IAWA Builetin n.s., Vol. 10 (3), 1989 lAWAListof microscopic features for hardwood idenrification 271

AXIAL PABENCHYMA

General commenls:When identifying an unknown, use the most obvious type of parenchyma pattern first and

then the less evident type or types. Be sure to use a broad ficld of view when deterrnining thepredorninant parenchyma pattern(s) from the n-ansverse section. Various combinations of thethree general types (Apotracheal, Paratracheal, and Banded) described below may be prescrit in agiven wood.

75. Axial parenchyma absent or extremely rare

Definizion:

Axial parenchyrna absent or extremely rare = as per feature descriptc,r, fig. 83, e.g.,Berberidaceae, Punicaceae, Violaceae, Homaliu,nfoetidwn, Sconellia coriacea (Hacourtiaceac),Sonneratia spp. (Sonneratiaceae).

Comment:li is necessary to study longitudinal sections in combinajion with transverse sections to be sure

axial parenchyma is absent or extremely rare (i.e., very difficult to find; only a few stands persection). This feature may be used in combination with 'axial parenchyma scanty paratracheal'(feature 78) and/or 'axial parenchyma diffuse' (feature 76), if, despite the scarcity of parenchy-ma strands, the distribution is clear.

APOTRACHEAL AXIAL PARENCFIYMA

76. Axial parenchyma diffuse77. Axial parenchyma diffusein.aggregates

Dejinirions:

Apotracheal axial parenchyma = axial parenchyma not associated wth the vessels.

Axial parenchyma diffuse = single parenchyma sirands or pairs of strands distributedinegularly among the fibrous elements of the wood, fig. 84, e. g., Aspídosperrna polyneuron(Apocynaceae), A/nus glutinosa (Betulaceae), Goupia glabra (Celastraceae), Cornus mas (Cor-naceae), Apodytes di,nidiata (Icacinaceae), Crataegus spp. (Rosaceae), Santalum album (San-talaceae).

Axial parenchyma diffuse-in-aggregats = parenchyma strands grouped into shortdiscontinuous tangential or oblique lines, fig. 85, e.g., Durio spp. (Bombacaceae), Hura crepi-tans (Euphorhiaceae), Ongokea gore, Strombosia pusrulata (Olacaceae), Agonandra brasiliensis(Opiliaceae), Dalbergia sreven.sonii (Pap ilionaceae), Prerospermum spp. (Sterculiaccae), Tiliaspp. (Tiiiaceae).

Fig. 83. Axial parenchvnia absent or extremely rare (featurc 75), Homaliu,nfoezidum, x 75. -Fig. 84. Axial parenchyma diffuse (feature 76), Alnus glutinosa,x 115. - Fig. 85. Axialparenchyma diffuse-in-aggregates (feature 77), Agonandra brasiliensis, x 45. - Fig. 86. Axialparenchyma scanty paratracheal (feature 78), and aiso scanty diffuse (feature 76), Dilienia pul-cherrima,x 115.

flii .tiIJ(

272 IAWA Builetin ris., Vol. 10(3), 1989 IAWALisL of microscopic features for hardwood identification 273

Co,nmenrs:Because there is a continuous range from parenchyma extrernely rare, diffuse, diffuse-in-

aggregatcs, to parenchyma in narrow bands (feature 86) or scalariform (feature 88), for sometaxa it wil] be necessary to record more than one feature for apotracheal parenchyma. Diffuseand diffusc-in-aggregates frequently occurincombination. Record (1944) referred to diffusc-in-aggregates parenchyrna as reticulate. This list does not follow that usage, but uses rcticulate todescribe a type of barided parenchyma, sce feature 87.

Caurions: Although by defiuiition apotracheal parcnchyma is not associated with vesseis, woodswith abundant diffuse or diffuse-in-aggregate parenchyma rnay exhibit several strands touchingihe vessels. Such random contacts should not be recorded as parairacheal parenchyma.

Apotracheal diffuse parenchyma sornetimes occurs primarily near the rays ('ray adjacentparenchyrria' of Carlquist 1988), and shou]d not be confused with sheath celis in rays (feature110),

PARATRACHEAL AXIAL PARENCHYMA

78. Axial parenchynia scanty paratracheal79. Axial parenchyma vasicentrie80. Axial parenchyma aliform

81. Axial parenchyma lozeuge-aliform82. Axial parenchyma winged-aliform

83. Axial parenchyma confluent84. Axial pa renchyma unilateral pa rat racheal

Definitions:

Axial parenchyma paratracheal = axial parenchynia associated wih the vesseis or vas-cular tracheids; Lypes of paratache.al parenchyma are scanty paratracheal, vasiccntric, aliforrn(subtypes: lozenge-aliform, winged-a]ifonn), confluent, and unilateral paratracheal.

Axial parenchyma scanty paratraclieal = occasiojial parenchyma celis associated withthe vesseis or an incornplete sheath ofparenchyma around Lhe vesseis, lig. 86, eg. Pistacia vera(Anacardiaceae), Scierolohium spp. (Caesalpiniaceae), Dillenia puicherrima (Dillerriaccae), Eiy-throxylu,n ,nannii (Erythroxylaceae), Laurus nobilis (Lauraceae).

Axial parenchyma vasicentric = parenchyma celis forining a complete circular to ovalsheath around a solitary vessel or vessel multiple, Ílgs. 87, 88, e. g. Tachigali myr,necophylla(Caesalpiniaceae), Octomeles sunwrana (Datiscaceae), Phoebe porosa (Lauraceae), Khaya gran-d(foliola (Mcliaceae), Anadenanrhera spp., Ent-erolobiwn cyclocarpwn, Pipradeniastru,n africa-num (Mimosaceae), Olea europaea (Oleaceae).

Axial parenchyma aliform = parenchyma surrounding or to one side of the vessel andwith lateral extensions. For examples see Lhe two subtypes below.

Axial parenchytna lozenge-aliform parenchyma surrounding or to orie side of thevessels with lateral extensions forming a diamond-shaped outline, fig. 89, e.g., Albizia lebbek.Parkia gigantocarpa (Mimosaceae), Arlocarpus chaplasha (Moraceae), Microberlinici brazzavil-lensis, Ormosia fiava, Vataireci spp. (Papilionaceae), Quaiea rosca (Vochysiaceae)

Figs. 87 & 88. Axial parernhyrna vasjcentric (featurc 79). - 87: Parenchvuia sheath broad,Pip fade niastrum africanum, x 26. - 88: Parenchyma sheaih narrow, Khavn grandifoliola, x 45.

- Fig. 89. Axial parenchyma lozenge-aliforrn (features 80 and 81). Microberlinia brazzavillen-sts, x 29. - Fig. 90. Axial parenchyma winged-aliform (features 80 and 82), Brosimu.m rubes-cens, x 45,

274 - IAWA Bul]etin n.s., Vol. 10 (3), 1989 LAWA List of nhicroscopic_features for hardwood identification 275

1-'igs. 91 & 92. Axial parcnchyrna conflucnt (frature 83). —91: Parkiapen(Iuia arrowhead, notealso features 80 and 81, parenchyma ]ozenge-aliforrn), x 36, —92: Peltogyne confertiflora (notealso feature 84, unilateral parenchyma), x 45. Fig. 93. Axial parenchyma unilateral para-tracheal (feature 84), Caraipa grandiflora, x 45. - Fig, 94. Axial parcnchyma prcdominantlyparatracheal, Garcinia iwissirna (note also features 80, alifonii, and 83, confluent), x 45.

Axial parenchyma winged-aliform = parenchyma surrounding or to one side of thevesseis with the ]ateral extensions being elongated and narrow, fig. 90, e, g. Jacaranda copaia(Bignoniaceae), Termina/ia superba (Combretaceae), Brosimum spp. (Moraceae), Quassia ama-ra (Simaroubaceae), Gonystylus spp. (Thymelaeaccae).

Axial parenchyma confluent = coalescing vasicentrie or aliform parenchyrna surround-ing or to one side of two or more vesseis, and often forming irregular bands, figs. 91, 92, e. g.,Kigelia africana (Bignoniaceae), Caesalpiniaferrea, Peito gyne confertifiora (Caesalpiniaceae).Marmaroxyion racemosum, Parkia pendula (Mimosaceae), Ch/orophora tinctoria (Moraceae),Bowdichia nitida,Vatairea guianensis (Papilionaceae).

Axial parenchyrna unilateral paratracheal = paratracheal parenchyma forming semi-circular hoods or caps only on one side of the vesseis and which can extend tangentially orobliqucly in an aliform or confluent or banded pattern, fig. 93, e.g., Aspidosperrna desman.thum (Apocynaceae), Caraipa grandiflora (Borinetiaceae), Peito gyne conferíiflora (Caesalpi fia-ceae), Mammea bongo (Guttiferae), Dilobeia thouarsii (Proteaceae).

Comments:Scanty paratracheal includes what has been described iti the literature as iricomplete vasicen-

inc.Some woods have vasiccntric, aliform, and confiuent paratracheal parenchyma. ConflueLu

often intergrades with banded and may be recorded or used in combination with features forhand width (85-86). Feature 80, 'Axial parenchyma alifornf, is included as a general catcgoryto 1) describe those woods that clearly have aliforni parenchyma, but in which it is difficult todecide whether it is lozenge- or winged-alifonn, and 2) allow use ofinformation from the litera-ture that does not differcntiate between these two types. Features 81 and 82 are used in combi-nation with frature 80.

Feature 84 'unilateral paratracheal parenchyma' is used in cornbination with aliform and/orconfluent when the unilateral parenchynia extends lateraily or obliquely. Unilateral includes bothabaxial and adaxial because generally ii is not possible to discinguish between the two in a woodfragment.

Woods with several types of paratracheal parenchyma co-occurring and/or intergrading havebeen assigned the general descriptor 'parenchyma predominantly paratracheal' by severalauthors (fig. 94).

Caution: Vasicenti-ic/vascular tracheids are often thinner-wal]ed than ground tíssue tlbres, andin cross sections may be confused with axial parenchyma. Examine longitudinal sections todetennine whether vasicentric/vasctdar tracheids or axial parenchyma surrounds the vesseis,

o

276 - IAWA Bulietin n.s., Vol. 10 (3). 1989

BANDED PARENCHYMA

85. Axial parenchyma bands more than three cells wide86. Axial parenchyma in narrow bands or tines up to three cells wide87. Axial parenchyma reticulate88. Axial parenchyma scalariform89. Axial parenchyma in marginal or in seemingly marginal bands

Definitions:

Parenchyma bands more than three edis wide = as per feature descriptor, fig. 95,e.g., Dicorynia paraen.sis (Caesalpiniaceae), Entandrophragma candoliei (Meliaceae), Ficus re-tusa (Moraceae), Lophira alata (Ochnaceae), !Jasyloxylon brasiliensis (Sterculiaceae), Erismauncinarwn (Vochysiaceae).

Parenchyma in narrow bands or lines up to three cells wide = as per feature de-scriptor, figs. 96, 98, e.g., Dialium guianensi.s (Caesalpiniaceae), Endospermum malaccensis(Euphorbiaceae), Bertholletia excelsa (Lecythidaceae), Dysoxylum frasera num (Meliaccae),Aurranelia congolensis (Sapotaceae), Hanwa klaineana (Simaroubaceae).

Parenchyma reticulate = parenchyma in continuous tangential lines of approxirnately thesarne width as the rays, regularly spaced and forming a network with them. The distance be-tween the rays is approxirnately equal to the distance between the parenchyma bands, lig. 97,e. g., Cleistopholjs spp. (Annonaceae), Diospyros discolor (Ebenaceae), Bertholletia excelsa,cariniana spp., Couratari guianensis, Eschwei lera spp. (Lecythidaceae).

Parenchyma scalariform = parenchyma in fairly regularly spaced fine lines or bands, ar-ranged horizontally or in arcs, appreciably narrower than thc rays and with them producing aladder-Iike appearance in cross section. The distance between the rays is greater than the distancebetween parenchyma bands, figs.99, 100, e.g.,Anisophyllea spp. (Anisophylleaceae), Onycho.petalum sp. and most other Annonaceae, Cardwellfa sublimis, Embothrium mucronatum (Pro-teaceae), Rhopalocarpus spp. (Rhopalocarpaceae).

Parenchyma in marginal or in seemingl y marginal bands = parenchyma bandswhich fonn a more or lcss continuous Iayer of variable width at the margins of a growth ringor are irregularly zonate, figs. 101, 102, c. g- Jntsia hijuga (Caesalpiniaccae), Juglans regia(Juglandaceae), Cryptocarya moscJzaza (Lauraceae), Liriodendron zulipifera, Michelia compressa(Magnoliaceae), Cedrela spp., Swierenia spp. (Meliaceae), liorsfieldia subglobosa (Myristica-ceae).

Comments:Parenchyma bands may be mainly independent of the vesseis (apotracheai), definitely asso-

ciated with the vesseis (paratracheal), or both. Bands may be wavy, diagonal, straight, contiflu-ous or discontinuous (the latter often intergrading with confluent). The nurnber of bands per mmvaries and may be useful as a diagnostic feature in some groups. Bands over three celis wide arevisible to the unajded eye. For woods with reficulate, scalariform, or marginal parenchyma, theband width (either fé-atures 85 or 86) also should be recorded.

In the past, some anatomists (e. g., Record 1944) have used the term reticulate for abundantdiffuse-in-aggregates parenchyma with numerous short interrupted lines.

Sometimes marginal parenchyma bands are associated with axial interceliular canais. In sometemperate woods there are discontinuous bands/lines of parenchyma at the growth ring margin;this condition also should be described as 'marginal'. Marginal parenchyma includes terminaland initial parenchyma, and seemingly marginal includes what has been called irregular zonatebands.

IAWA List of microscopic features for hardwood identification

277

Fig. 95. Axial parenchyrna iii hands more than three edis wide (feature 85), Ficus retusa, x 45.- Fig. 96. Axial parenchyma in narrow bands or lines up to three edis wide (feature 86)..4utranella congolensis, x 45.

278

IAWA Builetin n. s., Vol. 10(3), 1989 IAWA Listof microscopic_features for hardwood identification - - 279

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Fig. 97. Axial parenchyrna reticulate (feature 87), í3ertholleria excelsa (note also feature 86,parenchyma in narrow bands), x 45. - Fig. 98. Axial parenchyrna intermediate betweenreticulate and scalanform (featurcs 87 and 88 variable), Couratari guianensis, x 45. - Figs. 99& 100. Axial parenchyrna scalariforrn (feature 88). - 99: Onychopetalum sp., x 45. - 100:Parenchyma bands also 'festooned', Cardwellia sublirnis, x 15.

Figs. 101 & 102. Axial parenchyma in marginal or seetningly marginal hands (feature 89). -101: Inisia bijuga, Note also features 80, 81 (lozenge-aliform parenchyma), 83 (confluent), and86 (narrow bands); x 29. - 102: Michelia compressa, x 45.

280

IAWA Bulietin n.s., Vol. 10 (3), 1989 IAWA List of microscopicfeatures_for hardwood identification 281

AXIAL PARENCHYMA CELL TYPE/STRAND LENGTIT

90. Fusiform parenchyma cells91. Two edis per parenchyma strand92. Four (3-4) celis per parenchyma strand93. Eight (5-8) edis per parenchyma strarid94. Over eight ceiis per parenchyma strand

Definition.ç:

Fusifoi-m parenchyma = parenchyma celis derived from fusiform cambial initiais withoutsubdivisions or tip growtli. In shape they resembie a short fibre, fig. 103, e.g., Capparis spp.(Capparidaceae), Aeschynornene elaphroxvlon, Erythrina spp., Lonchocarpus spp. (Papiliona-ceae), Trplochiion scieroxylon (S tercu] iaceae), Buinesia spp., Guiacuin spp., Zygophyllurnspp. (Zygophyllaceae).

Parenchyma strand = a series of axial parenchyrna cells forrned through transverse divi-sion(s) of a single fusiform cambial initial cd.

Two cells per parenchyma strand, figs. 103, 104, e.g., Dalhergia spp., Lonchocarpusspp., Pterocarpu.s spp.(Papilionaceae),

Four (3-4) celis per parenchyma strand, fig. 104, e.g., Termina/ia spp. (Combreta-ceae), Ligusrtim spp., Syri;iga spp. (Oleaceae), Nesogordonia spp. (Sterculiaceae).

Eight (5-8) edis per parench yma strand, fig. 105, e.g., Nerium oleander (Apocy-naceae), Macaranga spp. (Euphorbiaceae), Fraxinus spp. (Oleaceae).

Over eight celis per parenchyma strand e.g., Bhesa spp. (Celastraceae), Lophiraspp. (Ochnaceae), Minquartia spp., Tetrasylidum spp. (Olacaceae).

Commenrs.

Type ai' parenchyma, fusiform vs, sirand, is dctermined frorn tangential sections. Fusiforniparenchyma celis are relatively uncomrnon and generaily occur in woods with storied structureand short axial elements. In some species, cornbinations of the above fea[ures occur, e. g. fiisi-fopn cdlls' and two cel]s per parenchyma sirand', or 'twa cel]s per parcnchyma srxand' and'four (3-4) celis per parenchyma strand'. Strand length can difíerbetwcen earlywood and late-wood of the sarne ring, ar between vessel-associated parcnchyma and parenchyrna which is notin concact with the vesseis. Record ali cornrnonly occurring strand lengths.

Cawion.' Be careful not to confuse uniseriate rays or septate fibres with strand parenchyrna. Donor determine number of ce]ls per strand from chambere.d crystalliferous sirands.

95. Uniignifled parenchyma

Definition:Uniignitied parenchyma = as per feature descriptor, fig. 106, e. g, Apeiba spp., Ente/ca

arborescens, Heliocarpus spp. (Tiliaceae), Laporteo srimtdans (Urticaceae).

Conuneni:Unlignified parenchyma usually occurs in broad bands, and is resu-icted to a small number aí

taxa.

Fig. 103. Fusiform parenchyma ce]Is (feature 90, left and right) and twa celis per parenchyrnasu'and (feature 91, left centre). Note also feature 120 (axial parenchyrna storied) and fcatiire 142(crystals in chambered axial parenchyina). Aeschynomcne e/aphroxylon, x 115. - Fig. 104.

Two (feanire 91) ia fom (feature 92) edis per parenchyma strand, Cordia abyssinica, x 115.

Fig, 105. Figiu (feature 93) ar over eight ceils (feature 94) per parenchyma strand, Bertholleíia

excelsa, < 115.—Fig. 106. Un]ignified parcnchyma (feature 95), Ente/ea arborescens, x 45.

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282 IAWA Bulietin n.s., Vol. 10 (3), 1989

RAYS

RAY WIDTH

96. Rays exclusively uniseriate97. Ray width 1 to 3 celis98. Larger rays commonly 4- to 10-seriate99. Larger rays cornmonly > IO-seriate

100. Ra ys with multiseriate portion(s) as wide as uniseriate portions

Definitions:Ray width in celi numbers as per feature descriptors.

Rays exclusively uniseriate, fig. 107, e. g, Lophoperalwn beccarianum (Celastraceae),Termina/ia superba (Combretaceae), Hura crepitans (Euphorbiaceae), Castanea sariva (Faga-ceae), Populus spp. (Salicaceae).

Ray width 1 to 3 celis, fig. 108, e.g., Aucoumea klaineana (Burseraceae), Dialium gui-anense (Cacsalpiniaceae), Alseodaphne costa/is (Lauraceae), Albizia (Samanea) saman (Mimosa-ceae), Malus co,nmunis (Rosaceae).

Larger rays commonly 4- to 10-seriate, fig. 109, e.g., Acer saccharum (Aceraceae),Spondias mombin (Anacardiaceae), Anisoprera laevis (Dipterocarpaceae), Khaya anthotheca(Meliaceae), Celtis sinensis (Ulrnaceae).

Larger rays comrnonly > 10-seriate, fig. 110, e.g., Quercus spp. (Fagaceae), Fora-queiba guianensis (Icacinaceae), Rapanea spp. Myrsinaceae), Platanus spp. (Platanaceac), Card-we/lia sublimis, Grevi/lea robusta (Proteaceae), Tamarix aphyl/a (Tamaricaceae), Jacquinia revo-luta (Theophrastaceae).

Rays with multiseriate portion(s) as wide as uniseriate portions, fig. 111, e.g.,Anthodiscus amazúnicus, Caryocar cosraricense (Caryocaraceae), Srrombosja pustu/ata (Olaca-ceae), Ad/na cordifolia (Rubiaceae), and many Apocynaceae, Sapotaceae, and Euphorbiaceae.

Procedure:Determine ray width on the tangential section by counting the number of celis in the widest

part of the rays, perpendicular to the ray axis. When rays are of two distinct sizes (feature 103),record the width of the larger sire class in the database.

Commen Is:'Exclusivel y uniseriate rays' and 'rays> lO-seriate' are the Ieast comnion of the ray width

features. The categories for ray width match those of the Clarke (1938) and the Princes Risbor-ough multiple entry keys (Brazier & Franklin 1961). There are some taxa that may be separatedby uinerdistinctions within these categories, and in adescription more detailed information thanprovided by these categories would be desirable.

Caution: These features for ray width do not apply tu rays containing radial canais (feature 130)or to the rays composing an agegate ray (feature 101). Thus, for a wood with exclusively uni-senate rays, except for the rays with radial canais, describe the wood by recording feature 96 forexclusively unisenate rays and feature 130 for radial canais.

IAWA List of microscopic features for hardwood identification

283

Fig. 107. Rays exclusivcly uniscriate (featiire 96), Lophopetalum beccarianuin, x 75. - Fig.108. Ray width one to three celis (feature 97), Alhizia (Samanea) sarnan, x 29. - Fig. 109.Largcr rays commonly 4-10-seriate (feature 98). Note also shcath ecOs (arrow, feature 110);Celtis sinen-sis, x 29. - Fig. 110. Larger rays commonly> lO-seriate (feature 99), Cardwelliasubi/mis, x 19. Fig. 111. Rays with miiltiseriate portion(s) as wide as uniseriate portions(feature 100), Caryocar costaricense, x 115.

284 JAWABulietin n. s., Vol. 10 (3), 1989 IAWA List of microscopic features for hardwood identification 285

AGGREGATE RAYS

101. Aggregate rays

DeJlnirion:

Aggregate ray = a number of individual rays so closely associated with one another thatthey appear macroscopica]ly as a single large ray. The individual rays are separated by axialelements, e.g., many species ofAlnus (Bctulaceae), Carpinus, Cory!us (Corylaceae), Casuarjna(Casuarinaceae), Necepsia afzelii (Euphorbiaceae), Castanopsis, Lithocarpus, Quercus - ever-green species (Fagaceae), Enimotum orbiculatum (Jcacinaceae), Cryptocarya densflora (Lauia-ceae).

Commenrs:

There is variation in the size of the individual rays of aggregate rays. In some specics the ag-gregate rays are composed of narrow rays (figs 112, 113, e. g., Carpinus spp. - Corylaceae),while in others they are composed of broad rays (figs. 114, 115, e. g, Empnotum orbiculatu,n -lcacinaceae).

Aggregate rays occur in few taxonomic groups.

Caution: Aggregate rays may be relatively infrequent inche taxa in which they occur, so theymay be easily overlookcd or absent in a small sample; therefore, this feature should preferablybe used posiive1y only.

RAY HEIGHT

102. Ray heiglit > 1 mm

Definition:

Ray height> 1 mm = the large rays commonly exceeding 1 mm in hcight, e.g., Guatteriaschomburgkiana (A nnonaceae), Anisoptera laevis (Dip terocarpaceae), Uapaca guineensis(Euphorbiaceae), Scotzellja coriacea (Flacourtiaceae), Barrington(a asiatica (Lecythidaceae), Pia-ianus occidentalis (Platanaceae), Paypayroia guianensis (Violaceae).

Procedure:

Determine total ray height in tangential section, along the ray axis.

Comnzent:

In this Iist of features, only one category for total ray height is used as was done in some ofthe earlier multiple entry keys (Clarke 1938; Brazier & Franklin 1961). More detailed ray heightdata generally are given in descriptions and may be helpful in distinguishing between taxa insome groups. Ray height is quite variable in some woods (particularly woods with markedlyheteroceilular rays), bui quite uniform in others (particularly woods with storied strucwre).

Figs. 112-115. Aggregate rays (feature 101). - 112 & 113: Carpinus herulus, aggregatc r,r:(ar) composed of narrow rays. - 112: Transverse section, x 20. - 113: Tangencial sectr.x 52. - 114 & 115: E,nmozum orbicularum. aggregate ravs (ar) composcd of rnu1tisriate

45. - 114: Transverse section. - 115: Tangential seclion.

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286 lAWABufletjn n.s., Vol. 10 (3), 1989 1 AWA List of microscopiC features for hardwood identitication 287

RAYS OF T\VO DISTINCT SIZES

103. Rays of two distinct szes

Definition:

Rays of two distinct sizes = when viewed in tangential section, rays form two distinctpopulations by their width and usually also by thcir height, figs. 116, 117, e.g., Acer saccha-rum (Aceraceae), Poga oleosa (Anisophylleaccae), Ilex aquifolium (Aquifoliaceae), Dilleniapentagyna (Dillcniaceae), Quercus spp. (Fagaceae), Dendrobwgia boliviana (Icacinaceae), Sca-phiwn macropodum (Sterculiaceae), Ternsrroernja spp. (Theaceae).

Commenis:

There are no limits for the size classes - the smaller rays may be 1- or 2- or 3-seriate, the]arger rays may be less than 5-seriate.

Generaily, to fit the feature definition, intcrmecliate rays should not exist between the twopopulations or be quite rate. Thus, when very large rays occur with a fcw rnedium-sized andmore numerous small rays (e. g, Fagu.$), feature 103 'rays of iwo distinct sizcs' may still beapplied.

Cautions: Vhether a wood has rays of two distinct widths cannot be deterrnined from the crosssection because in this view the long uniseriate wings of heteroceilular multiseriate rays might bcinterpreted incorrecdy as narrow rays.

Aggregate rays per se houId not be considercd as a separate ray size class. Only iri thosespecies where the aggrcgate rays are composed of much broader rays than thc nonaggregate raysdoes feature 103 apply, e. g,, severa] species of Ca.suarina (Casuarinaceae) and Quercus (Faga-ceae).

Figs. 116 & 117. Rays of two distinct sizes (feature 103). - 116: Ternstroemia sp., x 45. - 117;

Quercus gilva, x 29.

28')IAWA List of microscopic featurc.s for hardwood identilication

I1tlii t

'T.

288 IAWA Bulietin n.s., Vol, 10 (3), 1989

RAYS: CELLULAR COMPOSmON

104. Ali ray cells procumbent105. Ali ray celis upright and/or square106. Body ray ceiis procumbent with one row of upright and/or square niargi-

na! ceils107. Body ray ceiis procunibentwjth moslly 2-4 rows of upright and/er square

marginal celis108. Body ray celis procumbent with over 4 rows of upright and/or squarc mar-

ginal ceils109. Rays with procumbent, square and upright celis mixed throughout tlie ray

Definjrfons:

Procumbent ray cefi = a ray parenchyrna ceil with its longest dirnension radial as seen inradial section.

Square ray celi = a ray parenchynia ccli approximatel y square as seen in radial section.Upright ray celi = a ray parenchyrna cel] with its lorigest dirnension axial as seen in radial

section.

AR ray cetls procumbent, fig. 118, e. g., Acer spp. (Aceraceae), Tabebuia spp. (Bigno-niaceae), Alhizia spp. (Mimosaceae), Hannoa klaineana (Sirnaroubaccae)

Ali ray celis upright and/or square, fig. 119, e.g., Hedyosmum scabrum (Chloran-thaceae), Aucubajaponica (Cornaceae).

Body ray ceils procumbent with one row ol upright and/or square marginaicelis, fig. 120, e.g., Kalopanax pictus (Araliaceae), Aucm.mea klaineana (Burseraccae),Pseudocedrela kanschyi (Meiiaceae).

Body ray celis procumbent with mostiy 2-4 rows of upright and/or squaremarginal celis, fig. 121, e.g., Liquidainbarstyrac,Jlua (Hamameljdaceae), Carapa guianensis(Meiiaceac), Trecu lia africana (Moraceae), A/seis peruviana (Rubiaceae), Euscaphf.s spp, (Sta-phyleaceae).

Body ray eeils procumbent with over 4 rows of upright and/or square margi-nal cells, fig. 122, e.g., Wein,nannia descendens (Cunoniaçeae), Quintinia spp. (Escailortia-ceae). HomaIiumfoetid (Flacourtiaceae), Hu.'niria spp, (Humiriaceae), O?oschulzj spp.(Icacinaceae), Coffea spp. (Rubiaceae), Turpinia spp. (Staphvleaceae).

Rays with procumben, square and upright celis mixed throughout the ray,fig. 123, e. g, Guaerja spp. (Annonaccac),Xan,/jop1/u, lanceatum (Polygalaceae), Pometiapinna:a (Sapindaceae), Heliocarpus spp. (Tiliaceae).

Fig. 118. Ali ray edis procurnbent (feature 104), Acer cwnpcslre. x 115.-- Fig. 119. Ali rayecOs upright anrifor squarc (feature 105), Aucuba japonica, x 29.— Fig. 120. Body ray cellsprocumbeni with oric row of upright and/ar square marginal edis (feature 106). Fseudocedrelu

kotschyi, x 115.— Fig. 121. Body ray celis procumhent with most]y two to íoui' rows of up-right and/or square marginal cells (íeature 107), Campa guianen.sis .. x 114. Fig. 122. Bodyray celis procurnbent with mostly over 4 rows of upright aiidlor squarc marginal celis (feature108), Hornalium j.'etidwn. x 115. - Fig. 123. Rays with procumbeni, square and upright ccllsrnixed throughout thc mv (feature 1091, Xwtthophyl!wn lanceatwn, x 90.

290EAWA Builetin ris., Vol. 10 (3), 1989

Frocedure;

Use radial sections LO determine the cellular composition of rays because types of ray celi(procurnbent, upright, and square) are defined on the basis of their appearance in radial section.Generaily, upright and square cens, if presem in eomhinatjon with procumberiL celis, are locatedri Lhe marginal rows, i.e,, those rows at lhe top and bottom of lhe ray, and procumbcnt cells are

]ocatcd in lhe body (centre) of lhe ray.

In woods wih uniseriate and rnultiscriate rays - desenhe lhe celhila.r cocnposition of lhe mui-

tiseni ate rays, not lhe uniseriate rays. Some woods have more than onc category of ray type withrcspect to celiular composition, only record lhe rclatively common categonies.

Cornmen13-

The ceiluiar colnposition of lhe niultiseriate and uniseniate rays in [f ie sarne wood is notnecessariiy the sarne. In some woods, their uniseniate rays are cornposed oniy of upright celis,while thcir multiseniate rays are composed of both upright and procurabeni celis.

Hornoceilular rays are rays coniposed of a single ccli type; heteroce]lular rays are composedof two ar more ccli types.

Thc tens homogencous and hetemgenenus are used to describe ray tíssue as a whole. De-signating Krihs types (Kribs 1968) rnay be useful when describing a wood, but are not used inthis Iist. Roughly spealdng, Kribs homogeneous types correspond with feature 104 (ali ra y celisprocurnbent), Kribs heterogeneous 111with feature 106 (one row of upright and/ar .square mar-ginal edis), Kribs heterogeneous II with fcature 107 (2-4 rows af upright and/or square mar-ginal celis), Krihs heterogeneous 1 with feature 108 (more than 4 rows of upright and/or squaremarginal celis). H&wever, feature 108 also may partly ovenlap witb Kribs heterogcneotjs 11 II' ffiebody of the rays is very high.

IAWA List of microscopic features for hardwood identification 291

Cautions:Ray composition often varies betwecn juvenile and mature wood. Ia many species, rays mar

the pith may be composed entirely of upnight celis, while rays distant from lhe pith are com-posed largely of procumbent edis with only a few rows of upnight and/or square edis. Whencreadng a database, only examine mature wood samples or, for shrubs, lhe penipheral wood oflhe thickest available stems. When an unknown wood fragrnent is from a thin branch, do nor use

ray composition.Although in tangential section, marginal rows of upright and/or square edis often will ap-

pear as uniseriate margins, lhe presence of uniseriate margins alone is not a reliable indicator ofheteroceliular rays. Ia some woods (e, g., Carya spp. —Juglandaceac), there are uniseniate mar-' -.ginal rows visibie in tangential section, and these celis appear larger xhan the body edis, butwheri viewed in radial section these edis are procumbent, as are lhe edis of the rnultiseriatc por-

tion.Sheath celis (feature 110) or tile cells (feature 111) are not considered when deternilning ray

ceiluiar composition.Feature 109 only appiies if there is a mixture ar alteration of different ray cdl shapes xhrough-

out the ray, irrespective of whether it is in uniseriate or nnildseniate rays or ray portions. Feature109 does not appiy to woods with vertically fused rays (ar 'rays with alternating uniseriate andmultiseriate portions') where the uniseriate portions may be composed of square and uprightcells and lhe multiseniate portions ofprocumbent edis. Just lhe presence of sheath ce]is (feature110) or tile edIs (feature lii) also does not qua]ify a wood for frature 109.

293IAWA List of microscopic features for hardwood identitication

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IAWA Builetin n.s., Vol. 10 (3), 1989

SHEATH CELLS

110. Sheath celis

DeJlnition:

Sheath celis = ray cells that are located along thc sides of broad rays (> 3-seriate) as view-ed in tangential section and are larger (generaily tailer than broad) than the central ray celis, figs.124, 125, e. g., Ceiba pentandra (Bombacaceae), Cordia altiodora (Boraginaceae), Sainbucusnigra (Caprifoliaceae), Dipterocarpus lowii (Dipterocarpaceae), Stemonurus luzoniensis (Icaci-naceae), Ailanthus altissima (Simaroubaceae), Sterculia oblonga (Sterculiaceae).

Commenrs:Presence of sheath celis should be deterrnined from tangential sections. There is variability in

the frequency and distinctiveness of sheath celis. In some species most, if not ali, multiseriaterays have sheath cells which are much larger than the other ray celis, while in others sheath celisare not frequent and/or slightly larger than the adjacent cells. When identifying an unknownwood sample, do not use this feature as a flrst lime of approach unless it is well mai-ked.

Cautwn: Do not confuse sheath celis with tile cells (feature 111), which are always found in thebody of the ray as weli as the edges and are visible in both tangential and radial sections.

TILE CELLS

111. Tile celis

Definition:

Tile celis = a special type of apparently empty upright (rarely square) ray celis occurring inintermediate horizontal series usually interspersed among rhe procumbent celis, figs. 126-129,e. g., Durio spp. Neesia aitissinia (Bombacaceae), Guazutna spp., Kleinhovia hospira, Prero-spermum spp. (Sterculiaceae), Despiarsia spp., Moi/ia spp., and some species of Grewia (Tilia-ceae).

Commenrs:Tile edis sometimes have been classified into two groups: type Durio when they have the

sarne height as the procumbent ray celis, and type Pterospermum when they are higher. How-ever, this distinction is dubious because there are intergradations between the two, as in Gua-ruma (Sterculiaceae), and Grewia (Tiliaceae).

Tile edis do not occur in uniseriate rays, and as far as is known are restricted to the orderMalvales.

Figs. 124 & 125. Sheath celis (feature 110). - 124: Ceiba pentandra, x 75. - 125: Stemonuruluzoniensis, x 75.— Figs. 126-129. Tile celis (feature 111). - 126-128: Durio type, Neesiaalrissima, radial, transverse, and tangential section, x 115. - 129: Pterospermum type, Ptero-spermwn grewiaefoliurn, radial section, x 120.

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PERFORATED RAY CELLS

112. Perforated ray celis

Definition:

Perforated ray celis = ray celis of Lhe sarne dimensions or larger than the adjacent edis,but with perforations, which generaily are on the side walis connecting Iwo vesseis on eitherside of the ray, figs. 130-132, e. g., Combretwn Ieprosrachiuni (Combretaceae), Richeria race-mosa (Euphorbiaceae), Chaunochiton breviflorum (Oiacaceae).

Commenrs:The type of perforation in a perforated ray ccli may be simple, scalariform, reticulate, or for-

arninate, and does not necessarily coincide with the type of perforation plate occurring in thevessel elements of the sarne wood. For instance, Sloanea monosperma (Elaeocarpaceae) andRicheria racemosa (Euphorbiaceae) have simpie perforations in the vessei elernents and scalari-form perforations in Lhe perforated ray cells. In Siparuna (Monimiaceae) there is a range ofmultiple perforations in thc ray celis, but the vessel elemcnt perforations are simple and/or sca-iariform with variations depending on species.

Pcrforated ray celis have bordcrcd pits similar to the intervessel pits. They can occur mdi-vidually or in radial ortangential rows. Radial rows ofperforated ray edis with perforations inthe tanendai walls have been described as radial vesseis (Van Vliet 1976a).

Caution: Use this feature positively only and with some caution because spccies that have per-forated ray celis may have thein in such low frequency that they could easily have bcen over-iooked when creating a database, or exarnining an unknown.

DISJUNCTIVE RAY PARENCHYMA CELL WALLS

113. Disjunctive ray parenchyrna ccli walis

Definirion:

Disjunctive ray parenchyma ceil walis = ray parenchyma edis partialiy disjoined butwith contacts maintained through tubular or compiex wall processes, fig. 133, e. g., Funtuiniaafricana (Apocynaceae), Buxus sempervirens (Buxaceae), Crozon oligandrus, Glycydendrona,nazonicum, Suregada laurina (Euphorbiaceae), Malpighia incana (Malpighiaceae), Gardeniaimperialis, Randia armara (Rubiaceae).

Comrnent:Axial parenchyma nay also be disjunctive

IAWA List of rnicroscopic_features for hardwood identification 295

Figs. 130-132. Perforated ray celis (feature 112). - 130: Simple perforation in radial wai.I,Chaunochiron breviflorum, x 115. - 131: Reticulate perforation in radial wali, Richeria race-

mora, x 115. - 132, Sirnple perforation in tangential wali, Com brerum leptosrachium, x 290. --Fig. 133. Disjunctive ray parcnchyma ccli walis (feature 113). Malpighia incana, x 290.Figs. 134 & 135. Wood rayless (feature 117), t'eronica tr2erSii, x 115. 134: Transverse sec-

tion. 135: Tangential section.

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RAYS PER MILLIMETRE

114. 54/mm115. 4-12/mm116. ^ 121 mm

Definirions:As per feature descriptors, examples follow.^ 4/ mm, e. g., Guarreria schomburgkiana (Annonaceae), Cussonia arborea (Araliaceae).4-12/mm, e. g., Acer rubrum (Aceraceae), Acacia spp. (Mimosaceae).^: 12/ mm, e. g., Diospyros ,nespil(for?nis (Ebenaceae), Randia armara (Rubiaceae).

Procedure:The number of rays per linear unit is best determincd frorn a tangential section along a une

perpendicular to the ray's axis; it can also be deterrnined from a cross section. Make ten meas-urements and record the categories the range falis within.

Com ments:The feature 'rays 4-12 per mm' is more common than the features 'rays ^. 4 per mm' or12 per mm' (Metcalfe & Chalk 1950). The number of rays per mm cannot sensibly be de-

termined in woods with aggregate rays, or woods with very broad rays and mo distinct sizeclasses, e. g., Quercus spp. (Fagaceae).

W000 RAYLESS

117. Wood rayless

Definition:

Wood rayless = wood with only axial clements, figs. 134, 135, e.g., Arrhrocne,nu,n,nacrostachyum (Chenopodiaceae), Heimerliodendron brunonianum (Nyctaginaceae), Hebe sah-

czjolia, Veronica rraversii (Scrophulariaceae).

Commenr:Rayless woods are restricted to a small number of families (Carlquist 1988).

Caurion: In rayless woods with included phloem (e.g., several Chenopodiaccac. the conjunc-tive parenchyma (i.e., the parenchyma linking mo or more phloem strands) may forni radiaiextensions which resembie rays. In such woods there rnav be a continuum from short radi1wedges tu long radial strips to 'normal' rnuitiseriai ravs lhn r al. ) tl teLLue fd\

1es' should he iised i[li caution in such 'oods

L

298 IAWA Builetin as., Vol. 10 (3), 1989 IAWA List of rnicroscopic features for hardwood idendfication - - 299

118. Ali rays storied119. Low i-ays storied, high rays nonstoriect120. Axial parenchyma and/or vessei elemcrits storied121. Fibres storied122. Rays andlor axial elements irregularly storied123. Number of ray tier: par axial mm

Definitions:

Storied structure = cclls arranged in tiers (horizontal series) as viewed on lhe tangenrialsurface.

Ali rays storied, 1lgs. 136, 138, e. g, Dalbergia bariensis, Prerocarpus sansalinoides (Pa-piiionaceae), Quassia amara (Simaroubaceae).

Low rays storied, high rays nonstoried, fig. 137, e.g., Scaphium spp., Triplochitonscleroxylon (S tercul iaceae), Cercis canadensis (Caesalpiniaceae).

Axial parenchyma and/or vessel elements storied, fig. 136, e.g, Balanites aegyp-daca (Balanitaceae), Dalbergia bariensis, Sparziwnjunceum (Papilionaceae), Tarnarix spp. (Ta-maricaceae).

Fibras storied, 6g. 138, e. g, Quassia amara (Simaroubaceae), Ocwmeles sumacrana (Da-tiscaceae), Zygophyllu.in dumosum (Zygophyllaeeae).

Rays and/or axial elements irregularly storied = stories of rays and/or axial ele-ments not horizontal or straight, but wavy or oblique (synonym: in echelon), or only locallypresem, fig. 139,e.g., certain Leguininosae (Monopetalantlius, Teiraberlinia), Entandrophrag-rna cylindricwn (Meliaceae), Fraxinus alba (Oleaceae), Tieghemella spp. (Sapotaceae).

Number oF ray tiers par axial mm = as per feature descriptor.

Co,nments:The presence of storied structure should be deterrnined &om lhe tangential section, foi

lhe

radial section. These features can be recorded singly or ia combination as in some woods alielements are storied (e. g., Hibiscus tiliaceus -- Malvaccae, Cenrrolobiu,n paraense, Afrormosiadata - Papilionaceae), whiie in cahers various combinations of elernents are storied. Generally,if parenchyma is storied, the vessel elements also are storicd. Featare 122, 'rays and/or axialelements irregularly storied', is used in combination with lhe other features when appropriate.

There is variability within species and saniples. For instance, ia some samples ofSwietenia(Meliaccae) rays are defiriitely storied, in others irregulariy storied, and in still others rays areaol storied.

Tiers of rays are visibie at low magnification, or with lhe unaided eye or a hand lens, andappear as fina horizontal striations or ripple marks on the tangencial surface. Especiafly ia lheLeguminosae, which has many taxa with storied rays, the number of ray tiers per mm (feature123) can be useful in distinguishing genera and specics.

Absence of storied snuclure (features 118-123 abseni) is also oU diagnostic vaJue.

Caution: Storying of wide vessel elements may be obscured because oU ceil enlargement duringvessel development, and se it is best to examine lhe narrower vessel elements te determinewhether vcssel elements are storied.

Fig. 136. Ali rays storied (fearure 118) and axial parenchyrna and/ar vessel elements storied(feature 120), Dalhergia bariensi.s, x 75. Fig. 137. Low rays storied, high rays nonstoried(feature 119), Triplochiton scleroxylon. Note also features 120 (parenchyma storied) and 121(fibres storied); x 45. - Fig. 138. Fibras storied (feature 121), Quassia amara, x 45. - Fig.139. lrregularly storied structure (feature 122, hera expressed as rays ia echeion), Entandro-phragma cylindricwn, :x 45

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IAWA Bulietin n. s., Vol. 10(3), 1989

SECRETORY ELEMENTS AND CAMBIAL VARIANTS

OIL AND MUCILAGE CELLS

124. Oil and/or mucilage celis aSsociated with ray parenchyma125. 011 and/or mucilage edis associated with axial parenchyma126. Oil and/or mucilage celis present anlong fibres

Definitions:

011 celi = a parenchymatous idioblast fihled with ou; mostly, but not always, enlarged androunded in outhne, occasiona]ly of considerable axial extension, figs. 140, 141, e.g., Nectan-dra grandis, Ocotea glaucinia, O. tendia, Phoebe porosa and many other species of Lauraceae,Talaur,ia spp. (Magnoliaceae),

Mucilage ccli = a parenchymatous idiob]ast fihlcd with rnucilage; typically enlarged androunded in outline, occasionally of considerab]e axial extension (resernbling fibres), e.g., figs.142, 143, axial iii some specics of Endlicheria (Lauraceae), and in ray parenchyma of some spe-cies of Persea (Lauraceae).

Co,nments

Both oil cells and mucilage celis are commonly associated with axial and/or ray parenchynia,but may also occur among fibres. They are limired to very few woody dicotyledons and aresimilar to one another, except for iheir contents, which are easily removed during rnicrotechnicalprocedures (Richter 1977).

Because ii is not practical to distinguish beween oil and mucilage edis by thcir appearance,they are listed together. Various combinations of these features eccur togciher (see Baas &Gregory 1985; Gregory & Baas 1989),

IAWA List of microscopic features for hardwood identification 301

Fig. 140. Oil and/or mucilage cdlis associated with ray pare nchyma (feature 124), Ocoiea giau-cinia, x 115.— Fig. 141. Oil and/or mucilage edis associated with axial parenchyma (feature125, arrows), Ocotea glaucínfa. Note also feature 124, ujl and/or mucilage edis in rays; x 45,- - Figs. 142 & 143. Oil and/or mucilage cells presem among the fibres (feature 126), Ocoreaccneilci (elongated inucilage celis), x 115.– 142: Transverse secdon. - 143: Radial section.

IAWA List of microscopic features for hardwood identiflcation 303

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1NT1TRCELLI5LAR CANALS

127. Axial canais in long tangential lines128. Axial canais in short tangential lines129. Axial canais diffuse130. Radial canais131. Intercellular canais of traumatic origin

D/initions,

Interceilular canal = a tubular interceilular duct surroundcd by an epitheiium, gencrallycontaining secondary piam products such as resins, gums, etc., secretcd by the epitheliai celis.Interceiluiar canais may be oriented axialiy (axial/vertical interceliular canal), or radially (radial/horizontal interceilular cana], within a ray), figs. 144-151. Synonyms: gum duct, resin duct.

Axial canais in long tangential iines = more than five canais in a une, fig. 145, e.g.,Copaifera spp., Sindora spp. (Caesaipiniaceae), Dryobalanops spp, flopea spp., Neohalano-carpus spp., Parashorea spp., J-'enracme spp., Shorea spp. (Dipterocarpaceae). Synonym: con-cenic axial canais.

Axial canais in short tangential lines = two to five axial canais in a une, fig. 146, e. g.,Diprerocarpus spp. (Dipterocarpaceae).

Axial canais diffuse = randorniy distributed soiitary canais, fig. 147, e. g., Prioria copai-fera (Caesaipiniaceae), Anisoptera spp., Cotylelohium spp., Upuna spp., Vaiaria macrocarpa,Varica spp. (Dipterocarpaceac).

Radial canais = canais presem in rays, figs. 148-150, e.g., Pistacia spp., Tapirira guia-nen.sis (Anacardiaceae), Bursera gummzfera (Burseraceae), Shorea section Richetia (Dipterocar-paceae), and rnany other genera of Anacardiaceae and Burseraceae. Synon ym: horizontal canais.

Trauniatic canais = canais formed in response to injury, arranged in tangential bands,generaiiy irregular in outline and ciosely spaced, fig. 151, e. g., Terminaliaprocera (Combrcta-ceae), Liquidambar sryracflua (Harnamciidaceae), Carapa procera (Meliaceae), Prunus serorinu(Rosaceae), Balfourodendrorz riedelianwn, Murraya exolica (Rutaceae), Quassia amara (Sima-roubaceae).

Cornments:It is possibie to have a mixture of thesc features in one wood.In some species of Dipterocarpaceae, the size of the axial canais is useful in differentiating

species, i.e., whether the canais are small (diameter < 100 xm) or largc (diameter> 100 im).The colour of resins in canais of Dipterocarpaceae can also be usefui in identif-ication.

The effect of radial canais on ray shape (i.e., whether the canal niakes the ray fusiform inshape or not), size, and number of canais per ray are also usefui features.

Caurion: Traumatic canais may not occur consistently in a species, therefore, when identifyingan unknown, never use the absence of traurnatic canais.

Fig. 144. Axial interceliular canal, Parashürea srn)rhiesii, x 290,— Fig. 145. Axial intcrcellularcanais in iong tangential hnes (fcature 127), Shorea parsfo1ia, x 29. - Fig. 146. Axial inter-ceiluiar canais in short tangential lines (feature 128), Dipterocarpus grandiflorus, x 20. -- Fig.147. Axial canais diffuse (feature 129), Vareriamacrocarpa, x 29.

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IAWA J3ul]tin n. s., Vol. 10 (3), 1989

Figs. 148, 149. Radial canais (feature 130). 148: Bursera gurnmifera, x 70: - 149: Shorea h-pefo1ia (arrow), x 140.

IAWA List of rnicroscopic feawres for hardwoud identification

305

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Fig. 150. Radial canais (feature 130), Paraçhorea smythiesu. x 75. - Fig. 151. Jnterce11t11r

canais of u-aurnatic origin (feanire 131), Murraya e.xotica, x 115-

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307IAWA List of microscopie features for hardwood identification

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TUBES / TUBULES

132. Laticifers or lanniniíerous tubcs

Dejlnitio:

Tubes/tubules = ce].]s or series of cclls of indeterniinate lcngth, extending radially rir ver-iically (among fibres); according to specific contents mo Lypes can be distinguished.

Laticifers = tubes containing latex, the latex may be colourless or light yellow to hrown;laticiíers rnay extend either radially (in geriera of Apocynaceae, Asclepiadaceae, Campanulaceae,Caricaceae, Euphorbiaccae, Moraceae) or axial]y (interspersed aioong fibres and so Lar knownori]y from Moraceae), figs. 152-155. Synonyms: latex tubes, latex canaIs.

Tanniniferous tubes = tubes containing tannins, whiçh are reddish-hrown, in rays (so Larknown only froni Myristicaceae), Figa. 156, 157.

Corn,nenrs:Although latex is often light-coloured, and tannins are dark, colour is not a reliable diffcr-

ence, and chenical tesis for tannin are needed to verify tube contents. Structural differencesbetween the laticifcrs and tarininiferous tubes appear minor (Fujii 1988). Thereforc, thesc mofeatures are combiried into one descriptor. Latex traces are included in this clescriptor.

Tanniniferous tubes oftcn are difficult to recognise in tangcntial sections because in that vimtheir dirnensions may appear similar to the ray edis; examining radial sections shows tannini-ferous tubes to be longer than ray celis.

Figs. 152-157. Laticifers (latex tubes) or tarininiferous tubes (feature 132). - 152: Alsioniascholaris, laticifer, x 140. - 153: Dyera costulata, wide laticiíers, x 180. - 154: Crotorr pana-rnensis, laticifer with dark-staining contents, 290. - 155: Artocarpus conjnwjis, axial laticifcr.x 75. - 156 & 157: Horsfieldia subg/ohosa, tanniniferous tube in transverse and radial seclion(arrows), x 290.

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CAMBIAL VARIANTS

133 lncluded phloem, concentric134. Included phloem, diffuse135. Other cambial variants

Definrions:

tncluded phloem, coricentric = phloem sirands in tangential bands alternating withzones aí xylem aiicl/or conjunctive tissue, fig. 158, e.g., Avicennia spp (Avic.enniaceac,Suaeda monoica (Chenopodiaceae).

Incluided phloern, dilTuse = scattered, isolated phloeni strands. The phloem strands mavbe surrounded by parenchyma ar imperforate tiacheary elements, fig. 159, e,vomica (Loganiaceae). Synonym: included phloem, foraminate ar island type.

Other cambial variants = caegory for a variety of cambial variants inclj:rrcal, ílattened, and furrowed in cross section; axes with lobed ar furrowed xy1cn; isircc x:.1cm; compound, divided, corded and cleft xylem masses.

Comrnents:The features for includcd phloem type are based on the appearance aí [he wood, and do not

have devclopmental inferences - they are not defined on the basis of whether there is a sing]epermanent ca'mbium, ar successive cambia, ar whethcr the tissue surrounding the phloeniswands is xylern or conjunetive tissue. As pointcd oul by Mikesell and Popham (1976) andCarlquist (1988), it is desirable to restrici ihe term interxylary ph]oem to chose cases in which thephloem has been produced internal]y by a single cambiurn.

lncluded phioem of the concentric type very often intergrades with diffuse included ph]oem(e.g,, in many Chenopodiaceae); in all cases ofdoubt use both fcatures in species with concen-tric included phloem the phloein bands may branch and anastomose, and the conjunctive parco-chyma somedrnes fornis radial extensions resembling rays.

Because included phloem and other cambial variants are of regular occurrence iii the taxa inwhich they are founcl, lhe cerrn 'anornalous' niust be considered a misnoiner.

Feature 135 'other cambial variants' most frcqucntly occurs in iiana: for more inforinationsi±e Carlquist (1988),

Fig. 158. lncluded phloern, concentric (feattire 133, arrows), Suaeda ,nonoica. Note also radialextensions of conjunclive parenchyrna (feature 117, wood rayless, variable-): x 38. Fig. 159.lncludcd phloern, diffuse (feature 134, arrows), Strychnos nux-votnica, x 45.

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310 -- - IAWA Builetin n. s., Vol. 10(3), 1989 1 AWA List of microscopic_features for hardwoodidentification 311

I1

MINERAL INCLUSIONS

PRISMATIC CRYSTALS

136. Prismatic crystals present137. Prismatic crystals in upright and/or square ray cells138. Prismatic crystals in produmbent ray celis139. Prismatie erystals in radial alignment in procumbent ray cells140. Prisrnatic crystals in chambered upright and/or square ray celis141. Prismalie crystals in nonchambered axial parenchyrna celis142. Prismatic crystals in charnbered axial parenchyma cells143. Prismatic crystals in fibres

Definirions:

Prisrnatic crystals = solitary rhombohedral or octahedral crystals coniposed of calciumoxalate, which are birefringent under polarised light (fig. 160). Synonym: rhornboidal cxystal.

Chambered ceil = an axial parenchyma strand ceil or ray parenchyma ccli subdivided bysepta or b' thin to tliick celi walls.

Features 137-143 as per descriptors, examples foilow.

Prismatic crystals in upright and/or square ray cells, fig. 161, e.g.. Astroniumspp. (Anacardiaceae), Bursera spp. (Burseraceae), Khaya anthorheca spp. (Meliaceae), 1-lelico-stylis spp. (Moraceae).

Prismatic crystals in procumbent ray cells, fig. 162, e.g., Anogeissus laufolia (Com-bretaceae), Carpinus spp. (Corylaceae).

Prisrnatic crystats in radial aligument in procumhent ray celis, fig. 162, e. g.,Aspidosperma quebracho-bianco (Apocynaceae), A nogeissus bufo lia, Bucida buceras (Com-bretaceae), Secw-i nega perrieri (Euphorbiaceae), Ouratea su.rinarnensis (Ochnaceae), Gonystylusspp. (Thymclaeaceac).

Prismatie crystals in chambered upright andfor square ray edIs, fig. 163, e.g..Elaeocarpus cabomala (Elaeocarpaceae), Glycydena'ron a,nazonicum (Euphorbiaceae), Banara ni-tida (Flacourtiaceae), Byrsonima laevigara (Malpighiaceae), Fagara fiava (Rutaçeae).

Fig. 160. Prismatic crystals (feature 136), Drypetes keyensis, x 230.— Fig. 161. Prismaticcrystals in upright and/or square ray edIs (feature 137), Astronium graveolens, x 115.— Fig.162. Prismatic crystals in procumbent ray celis (feature 138) and in radial alignmcnt (fe.ature139), Anogeissus laufolia, x 75. - Fig. 163. Prismatic crystals in chambered (or divided) up-right and/or square ray cells (fearure 140), Elaeocarpus cabornala, x 290. - Fig. 164. Prísrnaticcrystals in nonchambered axial parenchyma edis (feature 141), Drypetes gerrardii, x 290. -Figs. 165-167. Prismatic crystals in chambered axial parenchyma celis (feature 142). - 165:Crysrals in short chains, Lithocarpus edulis, x 290. - 166 & 167. Crystals in long chains. -166: Tangential section, Parkiapenduln,x 115, –167: Radial section, tvfalpighia incana, x 115.

F. 1 6. ['nsmatic crvstals in flhrcs (feature 14) Ranara reja. .' 115.

U.IL -

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IAWA List of microscopic features for hardwood identification

313

Prismatic crystals in nonchambered axial parenchyma cells, fig. 164, e.g., Cei-ba spp., Ocliroma spp. (Bombacaceae), Drypetes gerrardii (Euphorbiaceae), Ficu..s spp. (Mora-ceae).

Prismatic crystals in charnbered axial parenchyma celis, figs. 165-167, e.g., Gil-

hertiodendron preusii (Caesalpíniaceae), Pentacrne contorta (Dipterocarpaceae), Lilhocarpus edu-lis (Fagaceae), Juglans nigra (Juglandaceae), Couratari spp. (Lecythidaceae), Malpighia incana(Malpighiaceae), Parkia pendula (Mimosaceae), Zanthoxylum hygrophila (Rutaceae), Manilkizraspp. (Sapotaceae).

Prismatic crystals in fibres, fig. 168, e.g., Heniandradenia chevalieri (Connaraceae),Banara regia (Flacourtiaceae), Triplaris americana (Polygonaceae), Punica granatum (Punica-ceae), Majidea zanguebarica (Sapindaceae).

Co,nments:Prismatic (rhomboidal) crystals are the most common type of ciystal in wood (Chattaway

1955, 1956). The relative abundance of prismatie crystals is variabie. In some species, crystalsare consistently abundam; in others, they are consistently prcsent, but not abundant; and in stillother species, they are present in some samples, but absent in other samples. In some taxa, crys-tais occur in only one ceil type; in other taxa, they occur in more than orle ccli type. In the iattercase, record ali features that apply.

Information on the specific location of crystals often is not available from the literature. Con-sequentiy, fature 136, 'prismatic crystals present' is useful in constructing a database fromexisting information. Feature 136 is recorded in combination with other applicable crystal fea-tures (137-143).

In some species, crystals occur throughout Lhe ray (for heteroceliular rays: features 137 and138 both present). In other species with heteroceliular rays they are restricted to the marginalrows of upright and/or square celis, upright and/or square cells in the body of the ray, or sheathcelis (feature 137 present, feature 138 absent). In yet others, crystals are restricted to thc pro-cumbent body ray celis (feature 137 absent, feature 138 present). This last condition is not com-mon and usually occurs in combination with crystals in a radial alignment (feature 139). The lat-ter feature may appiy tu ciystals m nonchambered as weli as chambered celis.

l'he descriptors 'prismatic crystais in chambered upright and/or square ray edis' (feature140) and 'prismatic crystais in chambered axial parenchyma celis' (feature 142) include a con-siderabie diversity in types of chambcred or subdivided celis (cf. Parameswaran & Richter1984) and, particularly for axial parenchyma, in length of the chains of crystalliferous chambersor subdivisions. In some taxa there are oniy a few charnbers in a series, in others there are longchains. Such inforrnation should be recorded in a description.

Cauzions: There are many genera in which prismatic crystals are regularly absent (e. g,, Diptero-cai-pus spp. - Dipterocarpaceae, Betula spp. - Betuiaceae, Liriodendron Spp. - Magnoliaceae,and Ti/ia spp. - Tiiaceae). But, when identifying an unknown, using absence of crystals is no[recommended because crystals are of sporadic occurrence in many other taxa (e. g., Acer spp. -Aceraceae, Quercus spp. - Fagaceae, and Ulmus - Ulrnaceae).

Care is needed to distinguish between crystals in septate fibres and crystals in charriberedaxial parenchyma celis.

DRUSES

144. Druses present145. Druses in ray parenchyma cells146. Druses in axial parenchyma celis147. Druses in fibres148. Druses in chambered cells

Dejlnirions:

Druse = a compound crystal, more or less spherical in shape, in which the many compo-nent crystals protrude from Lhe surface giving the whoie structure a star-shaped appearance,figs. 169-17 1, e. g., Hibiscus tiliaceus (Malvaceae). Syrionym: cluster crystal.

Features 145-148 as per feature descnptor, exampies foliow.

Druses in ray parenchyma edIs, fig. 169, e.g., Gledirsia triacanthos (Caesalpinia-ceae), Macaranga barreri, M. heudelotrii Euphorbiaceae), Colubrinaferruginea Rhamnaceae),Arnygdalus cammunis (Rosaceae), Celtis paniculata (Ulmaceae).

Druses in axial parenchyma cells, fig. 170, e.g., Dacryodes edulis (Biirseraceac),Terminalia catappa (Combretaceae).

Druses in flbres, e. g., Combretum fruticosum (Combretaceae).

Druses in chnmhered cells, fig. 171, e.g., Macaranga barteri, M. occidenralis (Euphor-biaceae), Banara regia (Flacourtiaceae).

Comrnenrs:Most of the existing rnultiple entry ke ys and the literature do not provide information on the

location of druses. Consequently, the feature 'druses preseni' is included so that this informa-tion can be used.

In a given species, druses may occur in one or more of Lhe ccli types, and the celis may becnlarged as well (feature 156).

OTHER CRYSTAL TYPES

149. Raphides150. Acicular crystals151. Styloids and/or elongate crystals152. Crystals of other shapes (mostiv small)153. Crystal sand

DeJinition.',.-

Raphides = a bundie of long needle-likc erystais, fig. 172, e. g .. Dilienia rericulara. Terracera boliviana (Diileniaceae), Pisonia Spp. (Nyctaginaceae), Psyc/lot ria recordiana (Ruhiaccac),Tetrarnerista crassfolia (Tcuamcristaccac). Viris vinifera (Vitaccae).

314 IAWA Bulietin n.s., Vol. 10 (3), 1989 IAWA List of microscopic features for hardwood identification 315

-i

.- ''...1 73

L:

lik174

Fig. 169. Druses (feature 144) in ray parenchyrna celis (feature 145), Hibiscus riliaceus, x 145.- Fig 170. Druses in axial parenchyma cells (features 144 and 146), Terminalia carappa,x 170. - Fig 171. Druses in chambered ray celis (features 144, 145 and 148), Banara regia,

x 290. - Fig. 172. Raphides (feature 149) in procumbent ray ceil, Vitis vinifera, x 290. -

Fig. 173. Acicular or needle-shaped crystals (feature 150), Gmelina arborea, x 675. - Fig.

174. Styloids (feature 151), Mernecylon memhrarnifolium (in included phloem), x 95. - Fig.

175. Elongate crystals (feature 151), Ligustrum vulgare, x 220. - Fig. 176. SmaiI cubic crys-

tais (feature 152), Aporu.sa villosa (in ray celis), x 290. - Fig. 177. SniaII navicular crystals

(f':iture 152), T,itsca reticulata. x 675.

Acicular crystals = small needle-like crystals, not occurnng in bundles, fig. 173, e.g.,Tecorna stans (Bignoniaceae), Cryprocarya glaucescens (Lauraceae), and Gmelina arborea (Ver-benaceae).

Styloids = large erystais at least four times as long as broad with pointed or square ends,fig. 174, e. g., Mayrenus obrusifolia (Celastraceae), Terminalia amazonica (Combretaceae), Gel-semium senpervirens (Loganiaceae), Me,necylon membranfilium (Melastomataceae), Ga/lesiainregrfo1ia (Phytolaccaceae), Gonystylus bancanus (Thymelaeaceae).

Elongate crystals = crystals two to four times as long as broad with pointed ends, fie.175, e g., Siphonodon pendulwn (Celastraceae), Ligustrum vu/gare (Oleaceae), Vires glabratá(Verbenaceae).

Crystals of other shapes (mostly smaH) = includes ali other shapes of crystals, figs.176, 177, e. g., cubic (e. g,, Aporusa viliosa - Euphorbiaceae), navicular (boat .. shaped) (e. g.,Litsea rericulara - Lauraceae), spindie-shaped (e. g., Dehaasia spp. - Lauraceae), pyramidal(e. g., Caryodaphnopsis ronkinensis - Lauraceae), tabular (e. g., Aniba spp. - Lauraceae), in-dented (e. g., Forestiera segregaza — Oleaceae), twinncd (e. g., Nesregis spp. —Oleaceae), etc.

Crystai sarid = a granular mass cornposed of very small crystals, fig. 178, e. g., Cordiasuhcordata (B oraginaceae), Acrinodaphne hookeri (Lauraceae), Bumelia obtusifolia (Sapota-ceae), and Nico riana cordzfolia (Solanaceae). Synonym: microcrystais.

Com,nents:Crystals, particularly the small ones, are best detected with polarised lightThese crystals are not comrnon, and their occurrence may be sporadic. Therefore, these fea-

tures should only be used in the positive sense. Raphides and styloids often occur in enlargedcelis, feature 156. For more information on crystal types. see Chattaway (1955, 1956) andRichter (1980).

Caurions: Care must be taken not to interpret a cross section of an elongatc or acicular crystal asa cuhic crystal.

lhe crystals in raphide hundies often scparate during sectioning.

OTHER DIAGNOSTIC CRYSTAL FEATURES

154. More than one crystal of about Lhe sarne size per celi or chamber155. Two distinct sizes of crystals per ccli or chamber156. Crystals in enlarged celis157. Crystais in tyloses158. Cystoliths

Definir jons:

Features 154-157 as per feature descriptor, examples follow.

More than one crystal of about Lhe sarne size per celi or chamber, figs. 179,182, e. g., Bouea opposirifolia (Anacardiaceae), Garcinia latissima (Guttiferae), Aniba dzsckeii(Lauraceae). Ligustrum vulgare (Oleaceae), Gmelina arhorea. Vires divaricara (Verbenaceae).

- IL'f

- i 1• .; Iç 11

316 IAWA Bulietin n.s., Vol. 10 (3), 1989 IAWA List of_microscopie features for hardwood identification - 317

Two distinct sizes of crystals per ceil or chamber, fig. 181, e. g_ Mangifera altis-sima (Anacardiaceae), Cordia bantamensis (Boraginaceae), Pentacme conrorta (Dipterocarpa-ceae), Zanthoxylum juniperinum (Rutaceae), Bumelia glomerara (Sapotaceae), Gonyszylu.s ban-canus (Thymeiaeaceae).

Crystals in enlarged celis (idiobiasts), fig. 183, e.g., Carpinus carolinianum (Coryla-ceae), Juglans nigra (Juglandaceae), Pyrts communis (Rosaceae), Citru.s auranrium (Rutaceae),Carne/lia japonica (Theaceae), Zelkova serrata (Ulmaceae).

Crystals in tyloses, fig. 184, e. g., Astronium graveolens (Anacardiceae), Cordia gharaf(Boraginaceae), Pera bumeliaefolia (Euphorbiaceae), Chlorophora tincroria, Pseudolmedia spu'-ria (Moraceae), Chrysophyllum aurarum (Sapotaceae).

Cystoliths = internal stalked outgrowths of the ccli wali that project into the ccii lumen andare composed of celiulose impregnated with calcium carbonate. They are irregular in shape andsometirnes cornpletely 611 a ccli, fig. 185, e. g., in some Trichanrhera spp. (Acanthaceae), Spa-rarra,uhelium spp. (Hernandiacae), and Opiiiaceae.

Comments:Generaily, there is ordy one crystal per ccli or charnber. However, two or more similar-sized

crystals, especially acicuiar and/or navicular, and cubic and/or rectangular crystals, may Occurin the sarne ccli or chamber. li is rare that there are two distinct sizes of crystals in the sarne cclior chamber. For more information, see Chartaway (1956).

For feature 156, 'crystals in enlarged edis (idiohlasts)', the enlargcd edis can be either rayor axial parenchyrna edis, or more rarely both. The crystals in enlarged edis may he prismaticcrystals, druses, raphides, or any other crystal type.

Cystoliths, as far as is known, occur only in the exampies given (Ter Weile 1980).

Caution: Raphides are bundies of crystals, but the whole bundie is considered as a singie unit,and so feature 154, 'more than one crysta.l per ccli or chamber', does not apply to raphides.Crystal sand should also not be coded under feature 154.

Fig. 178. Crystal sand (feature 153, arrowheads), Cordia suhcordata (in ray celis), x 290.Figs. 179 & 180. More than one erystal of about the sarne size per ccli or charnber (feature 154).- 179: In axial parenchyrna celis, Garcinia lati ssima, x 75. - 180: In ray edis, Bouea opposiii-folia, x 290.— Fig. 181. Two distinct sizes of crystals per cdl or chamber (feature 155), Cor-dia banramensis (in ray celis), x 290. - Fig. 182. Different size classes of crystals intergradingin some ray edis (feature 155 variable), but more than one crystai of about the sarne size per cciiin others (feature 154 present), Cordia abyssinica, x 115. - Fig. 183. Crystais in enlarged celis(featm-e 156), Citru.s aurantium, x 135. - Fig. 184. Crystals in tyloses (feature 157), Cordiagharaf, x 140. - Fig. 185. Cystoliths (feature 158), Trichanthera gigantea, x 220.

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SILICA

159. Silica bodies present160. Silica bodies iii ray celis161. Sulca bodies in axial parenchynia celts162. Silica bodies in fibres

163. Vitreous silica

Defitjtjons:

Silica bodies = spheroidal or irregu]arly shaped particles composed of silicon dioxide.Synonyms: sulca grains, silica inciusions.

Features 160 -162 as per feature descriptor, exampies follow.

Silica bodies in ray celis, fig. 186, e.g., in Tratrfnickia burserfolla, T. demararae (Bur-seraceae), Licania leptostachya (Chrysobaianaceae), Shorea lameilara (Dipterocarpaceae), Mezi-laurus irauba (Lauraceae), Vitex compressa (Verbcnaceae).

Silica bodies in axial parenchyma cells,fig. 187, e.g., inBomhax nervosum, Diste-monanjhus spp. (Bomhacaceae), Apuleia leiocarpa, D ialium guianense (Caesalpiniaceae).

Silica bodies in fibres, fig. 188, e.g., Canariwn hirsutum, Prorium neglectum, Trarti-nickia burserfaIia (Burseraceae), Ocotea pube ruia (Lauraceae).

Vitreous silica = silica that coats ccli walis or cornpletely fihis the ccli lurnina, fig. 189,e.g., Srereospermum chelonoides (Bignoniaceae), Hydnocarpus graciüs (Flacourtiaceae), Arto-carpus vriesianus (Moraceae), and Gynot-roches a.rlllw-is (Rhizophoraceae).

Procedures:

Sílica hodies: Silica bodies are observed with Lhe light microscope in radial sectioris of eithcrpermanent or temporary mounts or in celis that have been macerated, LI largo amounts of ex-tractives are present and the sulca bodies are difficult to see in section, hleach with a domcsticblcaching agent, rinse in water, heat in carbolic acid, and mount iri clove ou, or macerate a fewchips in any macerating fluid that removes most of the exlracives and lignin but not the silica,

At low magnification (4-10 x objective lens), si]ica bodies genera]ly appear as smaIl darknonbirefringcnt particles. At higher magnification (25-40 x objective lens), they have a 'giassy'appearance.

Vitreou.s sílica.' Thoroughly macerate chips or splinrers, leave the wood iii the maceratirigsoludon until ii is white. Decant the macerating tluid, add water, rinse, decant, and repeat mui]Lhe solution is clear. Place some macerated wood on a slide: warrn ilie slide on a hotplate untilthe macerated wood is dry. Aliow the slide to cool, and then add 2 to 3 drops of concentratedsu]furic acid to dissolve ihe ceilulose. Add a cover s]ip and observe the cel]s under a light micro-scope ai low magnification. Vitreous silica appears like pieces of translucent vessel clementsand fibres. To distinguish undissolved celis from vitreous silica use polarised light. Undisso]vededIs are bircfringent, whereas vitreous silica is not. Vitreous sulca can also be recognised inweil-bleached sections bccause of irs 'glassy' appearance.

Fig. 186. Silica bodies present (feature 159) in ray edis (feature 160), Shorea lamellata, x 150.- Fig. 187. Sulca bodies in marginal ray celis and axial parenchyma edIs (features 159, 160,and 161), Apuleia lelocarpa, x 75. - Fig. 188. Silica bodies iii fibres (features 159 and 162),Ocotea ci. puberula. x 115. - Fig. 189. Viu-enus silica (feature 163), Hvdnocarpus gracilis,x 5(}.

320

IAWA Bulietin n. s., Vol. 10(3), 1989

IAWA List of microscopic features for hardwood identification 321

Cornmenss:Silica bodies rnost often are rcstrictcd to ray celis, particularly the marginal or upright edis.

Sometimes they are rcsicted to axial parerichyma; somctimes thcy oceur in both ray and axialparenchyma. Sílica bodies rarely occur in fibres, but if lhey do lhe fibres usually are septate.

Wheiher silica occurs in aggregations, as irregularly shaped or globular bodies, or whetherthe silica bodies have a smooth or verrucose surface may be diagnostic in certain groups andneeds to be re.corded in a description. For more information on silica bodies, see Amos (1952),Ter Weile (1976), and Koeppen (1980).

Cautions: When looking for silica bodies, do not use glycerin as a mounting medium becauseits refractive index niakes it difficult to detect silica bodies.

Hydrofluoric acid, which is sometirries used to soften wood, wili dissolve the silica bodies.

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1B2<164

IIs:fZ

APPENDIX

Non-anntomical Information

GEOGRAPH1CAL DISTRIBUTION (fig. 190)

164. Europe and temperale Asia (Brazier and Franklin region 74)165. Europe, excluding Mediterranean166. Mediterranean including Northern Africa and Middle East167. Temperate Asia (China), Japan, USSR

168.. Ceniral South Asia (Brazier and Franidin rcgion 75)169. India, Pakistan, Sri Lanka170. Burma

171. Southeast Asia and the Pacific (Brazier and Franklin region 76)172. Thailand, Laos, Vietnam, Cambodia (Indochina)173, Indomalesia: Indonesia, Philippines, Malaysia, Brunei, Singapore, Papua New

Guinca, and Solomon Islands174. Pacific Islands (including New Caledonia, Samoa, Hawaii, and Fiji)

175. Australia and New Zealand (Brazier and Franktin region 77)176. Australia177. New Zealarid

178. Tropical mainland Africa and adjacent islands (Brazier and Franklin regiori 78)179. Tropical Africa180. Madagascar & Mauritius, Runion & Comores

181. Southern Africa (south of the Tropic of Capricorn) (Ilrazier and Franklin rcgion 79)182, North America, nonh of Mexico (Brazier and Frarddin rcgion 80)183. Neotropies and temperate Brazil (Brazier and Franklin region 81)

184. Mexico and Central America185 Carrihbean186. Tropical South America187. Southern Ilrazi]

188. Temperate South America including Argentina, Chile, Uruguay, and S. Paraguay (Brazierand Franklin region 82)

Cü,nments.'There is no single ideal way of dividing the world. Thc abovc is a mixture of political and

hiogeographica] criteria. It retains the major geographical regions of Brazie.r and Franklin(1961), but some regions are subdivided so that more prccision is possible.

HABIT

189. Tree190. Shruh191. Vine/liana

Definjtion.ç:Fig. 190, Geographical distribution (feaures 164-188).

Tree = woody perennial piam with one main stem usuatly over 3 Tnetres tal],

R

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IAWA Builetin n.s., Vol. 10 (3), 1989 IAWA List of microscopic features for hardwood identification 323

Shrub = a woody pererinial plant usual]y with several stems and usually Iess than 3 meti-esuilI at maturity.

Vine/liana = any plant witli a long relativel y thin siem that c!imhs along a suppnrt or trailsalong lhe ground.

Comments:There wifl be overlap between these categorics in some species, and two or more, rarely ali

three,may apply.

WOOD OF COMMERCJAL HPORTANCE

192. Wood of commercial importancc

This category is intended for woods of both historical and current commercial importance.The term ofcommereial importance' is somewhat vague, and should be used with caution whenidentifying an unknown. But when identifying certain wooden artefacts, C. g., fiirniture. ii canbe helpful to segregate comrnercial species from noncommercial species.

SPECIFIC ORA vrry

193. Basic specific gravity 10w, ^ 0.40194. Basic specific gravity medium, 0,40-0.75195. Basic speeilie gravity high, ^ 0.75

Defini:ion.s:

Basic specifie gravity = ratio of lhe oven-dry weight of a piece of wood to the weight oflhe water displaced by lhe wood when it is completely swollcn (i.e., green volume). Examplesfor lhe feature categories follow.

Basic speciíic gravity Iow, :!^ 0.40, e. g., Dyera co.rtulata (Apocynaceae), Ceiba spp.,Qchrwn spp. (Bombacaceae), Populus balsamfera (Salicaceae). Triplochton spp. (Stercuiia-ceae), Ti/ia spp. (Tiliaceae).

Basie speciflc gravity medium, 0.40-0.75, e.g., Acer saccharum (Accraceae). Be-tuia lenta (Benhlaceac), Carapa guianensis, Khava rardjf!iiia (MeiLeae). iruns aniercana

(Oleaceae), Tectona spp. (Verbenaceae).

Basic speciíic gravity high. ^ 0.75, e. g ..As rrwuum 2reveo1ens (Anacard iaçc)Ocotea rodiei (Lauraeeae), Dalbergia melancwlon (Papilionaceae), Maniíkarn bidenrata (Sap)taceae), Guaiacwn spp. (Zygophyl]aceae).

Com rnenrs:Density is the weight of a substance (mass) per uni[ volume: speciflc gravity (s.g.) is lhe

rario of the density of a material to lhe density of water and, conscquently, specific gravity doesnot have units. For purposes of compucing speci fie gruvily of wood, wood density uses lheoven-drv weight of wood as lhe numerator, Because lhe volume of wood changes with changesin moisture content bclow fibre saturation point, it is neccssarv lo specify the muislure conreni ai

which specific gravity is detemiined. Basic specific gravity (Bsg), which is based on the greenvolume (wood fully swollen, moisture coritent of fibre saturation point or higher) is one of lhemost commonly cited values (Panshin & DeZeeuw 1980).

Qffier values often given for wood include basic density (Bd) which is equal to lhe oven-diyweight of woodfgreen volume and which has units (g/cm 3 , kg1m 3 ' or lbs/ft3 ). To convertfrom basie specific gravity (Bsg) to basie density (Bd) rnultiply lhe basic s.g, by lhe density ofwater as is shown below:

Bd in gfcni 3 = Bsg x 1 glcm3Bd in kg /M3 = Bsg x 1000 kg/m3Bd in Ibs/ft 3 = Bsg ' 62.4 1b51ft3

Therefore

Bsg of 0.4 = Bd of 0.4 g/crn3. 400 kg/m 3 , or 25 lbs/ft3Bsg of 0.75 = Bd of 0.75 g/cm 3 , 75 kg1m3 , or 46.8 1b5/ft3

HEARTWOOD COLOUR

196. Fleartwood colour darker than sapwood colour197. Heartwood basically brown or shades af brown198. I-teartwood basically red or shades of red199. Ileartwood basically yellow or shades of yellow200. Heartwood basically white to grey201. Fleartwood with streaks202. Heartwood not as above

Definitions:

Heartwood colour darker than sapwood colour, e.g,, Astronium spp. (Anaeardia-ceae), Tabebuia guayacan (Bignoniaceae), Acocia koa (M.imosaceae), Morus alba (Moraceae),Robinia spp. (Papilionaceae).

Heartwood basically brown or shades of brown, e,g., Quercus alba (Fagaccae),Albizia (Samanea) saman (Mimosaceae), Morus rubro (Moraceae), Eucalyptus giobulus (Myrta-ceae), Robinia spp. (Papilionaceae).

Heartwood basically red or shades of red, e. g., Brosimum rubescens (Moraceae),Prerocarpus macrocarpus (Papilionaceae), Sickingia spp. (Rubiaceae).

Ileartwood basically yellow or shades of yellow, e.g., Enantia chloranrha (Anno-rsaceae), Buxus spp. (Buxaceae), Schaefferiafrutescens (Celastraccae), Gossypiospernium spp.(Flacourtiaceae), Ciadrastis iutea (Papilionaceae).

Heartwood basically white to grey, e.g., Jiex opaco (Aquifoliaceae), Didymopana.xspp. (Araliaceae), Ceiba spp. (Bombacaeeae), Hura spp. (Euphorbiaceae), Cecropia spp. (Mo-raceae). Simarouba spp. (Simaroubaceae).

Heartwood with streaks, e. g., Dracontomelon dao (Anacardiaceae).

Heartwood not as above = colours such as black, purple, orange, green, as in Diospy-ros ebenum (Ebenaceae), Peltogyne Spp. (Papilionaceae).

324 IAWA Bulietin n.s, Vol- 10 (3), 1989

IAWA List of mioscopic feanires for hardwood identi6cation -325 1Procedure:

Time and exposure to light may alter Lhe appearance or vividness of Lhe colour. Thercforc,it is best to determine colour from a freshly cul tangentia] surface of a dry woocl sample. Theheartwood colour of recently felled trees often differs from that of dry wood samples. Thesedescriptors are for wood samples that are ai Ieast air-dry.

Comments.'

Feature 196, 'heartwood colour darkcr than sapwood colour', only can be used wben bothheartwood and sapwood are present, and is recorded in combination with Lhe other heartwoodcolour features (197-202). The heartwood of some species, e.g., Quercus alba (Fagaceae) andBetula lenta (Betulaceae), is not markcdly darker than Lhe sapwood, but can be distinguishedfrom it, so feature 196 applies to thcse taxa.

The variety of colours, shades, and combinations of heartwood colour make it impossible tocategorise ali of theni. In general, Lhe colour of heartwood is either brown, red, yellow, white,or some shade or combination of these colours. Basically brown heartwood is very corumon;basically red and basicafly yellow are rather rale; basicaily white or grey is rather frequent.

The heartwood colour of many taxa is not rcstricted to one colour, bui tu a combination ofcolours and, when appropnate, various combinations shou]d be recorded and may be used whenidendfying an unknown.

Examples of these combinations include: reddish-brown in Astronium spp. (Anacardiaceae),Hyrnenaea spp. (Caesalpiniaceae), Quercus rubra, Fagus spp. (Fagaceae), Khaya spp., Swiei-enia spp. (Meliaceae); yellow and brown in Disternonanthus spp. (Caesalpiniaceae), Chloropho-ra :inctoria (Moraceae), Adina cord(folta (Rubiaceae), Faga.ra spp. (I.utaceae), tvfastichodendronspp. (Sapotaceae).

Very light coloured woods would be recorded as combinations of white to grey and brownand/or yellow, c.g., Acer spp. (Aceraceae), Alstônia spp. (Apocynaceae), Anisoptera spp. (Dip-terocarpaceae), Gmeilna spp. (Verbenaceae).

Heartwood with streaks is always uscd in combination wíth Lhe general heartwood colour, asin Microberlinia spp. which lias brown heartwood with streaks.

'Heartwood not as above' is a 'catch-all' category for taxa with heartwood colours such asblack, green, orange, and purpie. This feature may be used alone (e. g., as for Diospyros ebe-nwn - Ebenaceae, which has distinctly black heartwood), but more commonly it will be used incombination with olher heartwood colours. For example, Lhe combinadon of basically brownand green occurs in Bucida buceras (Combretaceac), Ocoteu rodiei (Lauraceae), Liriodendronrulip (fera. Michelia spp., Talawna spp. (Magnoliaceae); Lhe combination of basically red, brown,yellow, and orange with streaks occurs in Centrolobiu,n spp, (Papilionaceae) and Aspidospermaspp. (Apocynaceae); lhe combination of brown, red, purple, black and orange with streaks oc-curs in Dalbergia spp. (Papilionaceae).

Cautions:Do not use heartwood colour features for ancient saniples, archaeological material, or other

samples whose colour has been altered by burial, time, lreatrnent, or decay.Be particularly careful when using lhe feature 'Heartwood basically white io grey', because a

whitish coloured sample may represent sapwood and not heartwood.

ODOUR*

203. Distinet odour

Definition:

Distinct odour = as par frature descriptor, e.g., Vihurnwn (Caprifoliaceae), Ceraropeta-

lum apetalum (Cunoniaceae), many specics ofLauraceae, Cedrela (Meliaceae), and Santalwn(Santalaceae).

Procedure:In dricd wood samples the chemicais responsible for Lhe odour rnay have voiatised froin lhe

surface, so it will be nccessary to expose a fresh surface, or take other measures to enhance Lheodour, e. g., add moisture by breathing on the wood, or wet Lhe wood with water and warm it.

Caucion: Odour is quite variable, and individual perceptions of odour often differ 'I'hercforc,use this feature with caution and only ia Lhe positive sente.

* Taste is deibcrately excluded because of safety considerations, particularly a concern thatsomeone may try tasting a wood whose contents could cause a severe allergic reaclion.

HEARTWOOD FLUORESCENCE

204. Heartwood Iluorescent

Definition:

Heartwood fluorescent = heartwood fluorescing when ilhiminated with longwave ultra-violei light, e.g., with a strong yellowish or greenish fluorescence in Anacardium excelsum(Anacardiaceae), Asimina spp. (Annonaceae), Aspidosperina eburneum (Apocynaceae), Robiniaspp. (Papilionaceae); with a slight tinge of orange fluorescence ia Mangifera indica (Anacardia-ccae), Varairen lundellii and Symphonia spp. (Guttiferae),Nauclea diderrichii (Rubiaceae); weak,yet positiva, fluorescence in many Annonaccae, Lauraceae, and Magnoliaceae.

Procedure:Samples for testing fluorescence must be frcshly surfaced; simply removing some shavings

with a knife is sufficient for exposing a fresh surface. Place samples i.mder a longwave (365 nm)ultraviolet (UV) iight ata distance of less than 10 cm. A high-intensity longwave UV lamp andobservation in a darkened room is recommended.

Co,nrnents:Fluorescent samples generally appear yellowish or greenish under Lhe UV iamp, although

some species show slight tinges of orange or pink.Samples that are not fluorescent rnay rellect some of Lhe UV light making the sample appear

slightly blue or purpie. Some samples with a yellowish heartwood, such as Chloroxylon spp,

(Rutaceae) and Gonystylus spp. (Thymeiaeaceae), are not fluorescent, but may seem tu have aweak yellow fluorescence because of reflection.

Absence of fluorescence can be irnportant in some famulies, e. g., Anacardiaceae and Legumi-nosae. See Aveila et ai, (1989) for a survey of fluorescence ia Lhe dicotyledons.

326 IAWA Bulietin n.s., Vol. 10 (3), 1989

IAWA Ust of microscopic features for hardwood identification 327

Caulions:This feature applies only to naturaily occurrmg fluorescence and not to fluorescence asso-

ciated with decay or pathological infections. Wood infected with decay organisms may fluorescewith sireaks, spots, or a mouled appearance, e.g., wetwood of Populus rre,nuloides (Salica-ceae) produces yellow fluoresceni streaks. Naturaily occurring fluorescence appears more uni -form.

Oven-drying of samples or exposure to high temperatures or other extreme environmentalcondirions may affect fluorescence propeilies.

WATER & ETHANOL EXTRACTS: FLUORESCENCE & COLOUR

205. Water extract fluorescent206. Water extract basically colourless to brown or shades of brown207. Water extract basically red or shades of red208. Water extract basicalty yellow or shades of yellow209. Water extract not as above210. Ethanol extract tluorescent211. Ethanol extract basically colourless to brown ar shades of brown212. Ethanol extract basically red or shades of red213. Ethanol extract basically yellow or shades of yellow214. Ethanol extract not as above

Procedures:

Preparation of extracts: Add enough thin heartwood shavings to cover the bottom of a cleanvial which is approxirnately 20 mm x 70 mm. Do not use splinters or chips, because the extrac-tion time is much longer than for shavings. For water extracts, cover the shavings to a depth ofapproximately 20 mm (approximately 5 ml) with distilled water that is buffered at a pH of 6.86.Packets of buffering agent are available from most scientific supply companies so that only thecontents of a packet need to be added to 500 or 1000 ml ofdistilled water to obtain the desiredpH. For ethanol extracts use 95% ethanol.

Dererminingfluorescence aí water & alcohol extracrs: Cover the vials and shake vigorous-ly for 10 to 15 seconds. Allow the shavings and solution to stand for 1 to 2 minutes, and thenhold the vial under a longwave (approximately 365 nm) UV lamp and check for extract fluores-cence. Generaily, extracts that fluoresce are bluish, but sornetimes they are greenish.

Determining colour of water and alcohol e.rrracts: Afrer determiriing the fluorescence of thewater and ethanol extracts, place the viais on a hotplate and bring the solution to a boi!. As soonas the solution boils, remove the vial and immediately determine the colour.

Com,nenrs & Examples for fluorescence:Examples of woods yielding water exrracts that fluoresce a hrilliant blue include Strychnos

decussata (Loganiaceae), Brosimum rubescens ( Moraceae), Olea europaea subsp. africana (Olea-ceae), Prerocarpus indicar (Papiionaceae), Zanrhaxylwnfiavwn (Rutaceae). Examples of woodwith weaker fluorescence of watercxtracts, but still positive, includeAcaciafarnesiana (Mimo-saceae) and Lonc/iocarpus capassa (Papilionaceae).

Examples of woods yielding ethanol extracts with bright fluorescence include Protorhus lon-gifolia (A naca rdi aceae), Cordia gerascanrhus (Boragi naceae), A cacia eriolol'a (Mimosaceae).

Examples of wood with weaker fluorescence of ethanol extracts, but still positive, include Kig-gelaria africana (Flacourtiaceae), Acacia melanoxylon ( Mimosaceae), Olea capensis (Oleaceae).

Sometimes the water extract of a species fluoresces, bus its ethanol extract does not (e. g.,Leucaena glauca - Mimosaceae). More often, the ethanol extract fluoresces, whi!e the waterextract does not (e. g., Afzelia quanzensis — Caesalpiniaceae, Lysiloma baha,nensis—Mimosa-ceae).

Commenrs & Examples for water & alcohol exrract colour:Water extract basically colourless tu brown or shades of brown is the most common of the

water extract feature colours.Examples of woods with water extract basically red or shades of red (feature 206) include

Brasilettia spp. (Caesalpiniaceae), Catha edulis (Celastraceae), Cunonia capensis (Cunoniaceae),and Mimusops caffra (Sapotaceae).

Examples of woods with water extract basically yellow or shades of ye!low (feature 2( y7) in-clude Gonioma ka,na.ssi (Apocynaceae), Albina adianthifolia, Acacia caffra (Mimosaceae).

Feature 209, 'water extract not as above' includes colours such as orange, hlack, and purpie.Various combinations of water extract colours occur as well.

Ethanol cxtract basically colourless to brown or shades ofbrown (feature 211) is the mostcommon.

Examples of woods with 'ethanol extract basicaily red or shades of red' (feature 212) includeRhus integrifolia (Anacardiaceae), l3aikiaea plurijuga, Peltophorum dubium, Swartzia madagas-cariensis (Caesalpiniaceae), and Berchemia discolor (Rhamnaceae).

Exarnples of woods with 'ethanol extract basically yellow or shades ofyellow' (feature 213)include Gonioma kamassi (Apocynaceac), Praeroxylon obliquwn, Zanrhoxylwnflavum ( Ruta-ceae), Balanites ,naugharnii (Zygophyllaceae).

Feature 214, 'Ethanol extract not as above', includes co!ours such as orange, black, andpurp!e.

For more information, see Dyer(1988) and Quirk (1983).

FROTH TEST

215. Froth test positive

Procedure:FolIow the procedure for preparing for lhe water extract tests. Add enough thin heartwood

shavings to cover the bottom of a clean via! approximately 20 mm x 70 mm. Do not use splintersor chips, because the extraction time is much longer than for shavings; if sawdust is used, ex-traction time will be less. For water extracts, cover the shavings to a depth of approximate!y20 mm (approximately 5 ml) with distilled waler that is buffered at a p11 of 6.86. Packets ofhuffering agent are available from most scientific supply companies so that only the contents ofthe packet need to be added to 500 or 1000 ml of distilled water tu obtain the desired pH.

Cover the vial and shake vigorously for 10 to 15 seconds. If natural saponins are present inlarge amounts, tiny bubb!es or 'froth' (like foam on a g!ass of beer) will be formed. A!low thevial to stand for approximate]y 1 minute from the end of the shaking. If 'froth' still completelycovers the surface of the solution after 1 minute, the test is positive. If 'froth' or bubbles formand then disappear within 1 minute, the test is negative. Ifonly some 'froth' remains around theedge of lhe vial (i, e., forming a ring of 'froth'), but does not cover the entre surface, the test isweakly positive.

328 IAWABuiletin n.s., Vol. 10 (3), 1989

IAWA List of microscopie features for hardwood identification 329

Com,nen:s & Exa,'nples:Positive 'froth' test reactions are produced by, e. g., Mora spp. (Caesalpiniaceae), Enrerolo-

bium cyclocarpum, Lysiloma baharnensis, Pseudosamanea spp. (Mimosaceae), Dipholis spp.,Mastichodendron spp. (Sapotaceae).

Wcaldy positive reactions (ring of froth) are produced by, e. g., Pelrophorum spp. (Caesal-piniaceae), Kiggelaria spp. (Flacourtiaceae), Ekebergia spp., Enrandrophragma spp. (Meia-ceae), Acacia nigrescens (Mimosaceae), Millerria spp. (Papilionaceae), and llerchemia spp.(Rhamnaceae).

For more information, see Dyer (1988), Quirk (1983), and Cassens and Milier (1981).

CITROME AZUROL-S TEST

216. Chrome Azurol-S test positive

Procedure:Prepare a 0.5% solution of chrome azurol-S reagent by dissolving 0.5 g of the dry chrome

azurol-S granules and 5.0 g of sodium acetate (buffer) in 80 ml of distiiled water. After thechemicais are compietely clissolved, add enough distilled water to make 100 ml of reagent. Thissolution is stable and can be used over a number of years. To test dry wood samples, use alieyedropper to appiy one or two drops of the solution to a freshly exposed end-grain.

In highly positive woods, a bright blue colour wii develop in a matter of minutes, e.g., Pogaspp. (Anisophylleaceae), Cardwellia spp. (Proteaceae), Symplocos spp. (Symplocaceae), aliVochysiaceae. In those woods which absorb the solution very slowiy, e.g, Anisophyllea spp.(Anisophylleaceae), Goupia spp. (Goupiaceae) or contain low concentrations of a]uminum, e.g.,Laplacea spp. (Theaceae), Henrieriea spp. (Melastomataceae), several hours niay be required forthe blue colour to develop.

Comment:Chrome Azurol-S tests for the presence of aluminum in both heartwood and sapwood. For

more information on this test, see Kukachka and Miller (1980).

Caution: Avoid decayed wood because chrome azurol-S is an indicator for some types of wooddecaying fungi.

BIJRNTNG SPLINTER TEST

217. Splinter burns to charcoal218. Splinter burns to a fulI ash: Colour of ash bright white219. Splinter burns to a fuIl ash: Colour of ash yellow.brown220. Splinter burns to a fuil ash: Colour of ash other than above221. Splinter burns to a partial ash

Definitions:

Charcoal = the blackened and charred remains of a splin ter, which usually burned slowlyandfor with difficulty, or the black and charred remnant of Lhe splinter with a fine thread ofblack or grey ash which may remam attached.

Fuil or complete ash = ash more or less retaining the shape of the original splinter.

Partial ash = ash that shrinks in size in comparison to the original splinter, lias a tendencyto drift away, and usually feels gritty when rubbed between the fingers.

Procedure:Prepare match-size (approximately 2 x 2 x 50 rum) splinters from sound outer heartwood,

insure the wood is aI least air-dry. The splinter must be ignited with a match, and devices (e. g.,Iighters) producing higher temperatures must be avoided. Ignite the splinter while it is held in avertical position wiffi a pair of tweezers/forceps. While the splinter is burning, hold it in a hoij

-zontal position and turn it slowly.Some timber species will hurn with relative case (e. g., Populus spp. - Saiicaceae), while

others rnay show considerable reluctance (e. g., Eucalyptus paniculara - Myrtaceae). If it ap-pears that the flame will extinguish before the splinter lias burned fully, combustion may beaided by gently returning the splinter to a vertical position and then back to horizontal.

After Lhe flame extinguishes, it is important to aliow the giowing part of the splinter to extin-guish before placing Lhe remnant on a cold surface.

Comments:Certain splinters may crackle or produce bright sparks (e. g., Termina/ia carappa - Combre-

taceae), whilc others may produce a characteristic smoke coloration (heavy black smoke in Fim-

dersia iaevicarpa - Rutaceae) or exude coloured compounds while Lhey burn. Ali these featuresrnay be recorded ia a description.

The descriptive classifications for appearance of the burnt splinter are those first recommend-cd by Dadswell and Burneli (1932). In some iiterature, buff is used to describe spiinters thathave Lhe colour of pale tanned leather, a yellowy brown, e. g., Eucaiyptus panicuiara (Myrta-ceae).

Apart from its use in CS1RO keys, Anonymus (1960) lias impiemented the feature and sug-gests that it is of little vaiue except in distinguishing between some timbers which are closelyrelated anatornically.

For further information on the burning splintcr test, which so far has only been used on avery limited scale, see Mann (1921), Welch (1922), Swain (1927), Dadswell and Burncli(1932), and Mennega (1948).

Caution: Code greyish-white ash as 'other than above', as the white is reserved for obviously(bright) white ash.

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IAWA LIST OF MICROSCOPIC FEATUIRES FOR

HARDWOOD IDENTIFICATION

by a Cornmittee of heInternational Association 01 Wood Anatorniqs

Veronica Angyalossy Alfonso, São Paulo, BrazilPieter Baas, Leiden, The Netherlands

Sherwin Carlquis, Claremont, California, USAJoao Peres Chimelo, São Paulo, Brazil

Vera T. Rauber Coradin, Brasilia, BrazilPierre Dtienne, Nognt-surMarne, France

Peter E. Gasson, Km, UKDietger Grosser, München, FRG

Jugo flue, Highett, Victoria, AustraliaKc co Kuroda, Kyoto, Japan

Regis B. MiLer, Madison, Wiscons3n, USAn Ogata, Tsukuba, Japan

Hans 'ieorg Richte:, Hamburg, FROI3en J. H. zer Wlle, Utrecht, The Netherlands

E1isabefl A. Wheeler, Raleigh, North Carolina, USA

Contenis

Preface ................................... 221cknow1edgernents ............................ 223

Explanatory Notes ............................ 225List of Features .............................. 226Name .................................... 233

natomical Features ........................... 234Apper;dix —Non-anatornl Inforrnation ............. 321

eferences ................................ 329

c ei; Sweeiiafruiicoa (Ferreir(.a spectabilis, Papilionaceae), n-ansver.se secon, x 115. Photograph by couriesy of eter E. Gasson (Kew, IJK) and taken

from a slide by Vera T. Rauber Coradin (Brasilia, Brazil).