74. CYPRIPEDIUM JAPONICUM var. FORMOSANUM Orchidaceae

Jeffrey Wood

Three species of slipper orchid are native to Taiwan (formerly Formosa), viz. C. debile Reichb.f., distributed in China and Japan, C. macranthum Sw., widespread from eastern Europe across northern Asia to Korea and Japan, and the plant figured here, C. japonicum Thunb. var. formosanum (Hayata) Ying, which is an endemic. In Taiwan they are all restricted to the mountains of the centre and north, at altitudes between 2500 and 3500m.

Of the 282 species of orchid currently recognized from Taiwan, C. japonicum var. formosanum is the largest flowered and undoubtedly one of the most attractive. In Taiwan it is known as ‘To-shieh lan’ or lady’s slipper orchid. The two curious pleated fishtail-like leaves give the plant a decorative appearance even when not in flower. The Taiwanese variety differs from typical var.jabonicum, which is native to China and Japan, in several details. The leaves are usually partly folded at flowering time, whereas in var. japonicum they are fully expanded. The peduncle is almost glabrous in var. formosanum, but distinctly hairy in var. japonicum. Hayata (191 6), when describing C. formosanum, comments that the ovary is also less hairy, although his latin description gives it as densely hirsute and similar to the plant figured here. Another feature ofvar. formosanum is the small triangular marginal tooth at the front of the lip which appears to be lacking in var.japonicum. The most obvious difference between the two varieties, however, is flower colour. Hayata (1916) describes the flowers of the Japanese plants as ‘more or less brownish’ and those from Taiwan as ‘whitish’. The flowers of var. formosanum are, in fact, generally white or pale yellowish, turning purple-pink after anthesis. The sepals, petals and lip are more heavily spotted with purple-red than those of var. japonicum. The tepals of var. japonicum are usually pale yellowish- green, spotted with red, and the lip is whitish to yellowish-pink with carmine spots. Ying (1 977) states that the flowers are unscented while Chow Cheng (1979) describes them as ‘very fragrant’. The plant figured here was only slightly fragrant.

In the wild C. japonicum var. formosanum inhabits mountain forests where it grows in damp leaf litter. Chow Cheng (1979) and Horng- Jye Su (1985) say that it may also be found in moist places with plenty of sunlight. I t is particularly abundant on the eastern slopes and

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Plate 74

Cypripedium japonicum var. formosanum VALERIE PRICE

northern part of the central mountain ranges of Taiwan. Such ornamental species as this are particularly vulnerable to the dep- redation of collectors and the plant figured here was an illegal importation into Britain and confiscated by H.M. Customs.

CULTIVATION. C. japonicum var. formosanum is grown in a cool greenhouse with a minimum night and day temperature of 5°C and 10°C respectively in the winter and 12°C and 20-25°C in the summer. Fifty per cent shading is provided from April until September, with about sixty per cent humidity and plenty of ventilation. Plants are grown in plastic pots, with a moist compost consisting of equal parts peat, loam, grit and forest bark. A very dilute foliar feed is applied once a week during the summer. Plants are repotted once a year during the spring.

DESCRIPTION. A terrestrial herb. Rhizome 2-3 mm in diameter, creeping, branching, with remote sheathing scales and short fasciculate roots at intervals. Flowering stems (5-) 10-1 5(-25) cm high, erect, glabrous, enclosed below by 5-8 obtuse imbricate sheaths, each 1-8cm long, apex 2-leaved. Leaves 10-1 3 cm long, 7-1 1 cm wide, almost opposite, sessile, flabellate from a very short sheathing base, apex rounded, apiculate or aristate, plicate, membranous, margin entire to erose, ciliate, undulate, sparsely puberulus on both surfaces, with 11-1 3 radiating primary nerves terminating and uniting at the margin to form an obscure marginal nerve, partially folded at flowering time. Znjorescence 1-flowered; peduncle 10-1 1 cm long, almost

Cypripedium japonieUm var. formosanum. A, synsepalum x 3; B, petal, x 3; C, dorsal sepal, x 3; D, lip, longitudinal section, x 1 ; E, column, side view, x 2; F, column, from below, x 2; G, staminode, side view, x 2; H, staminode, front view, x 2; J, ovary, transverse section, x 4.

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glabrous; floral bract solitary, 2.2-4 cm long, 0.8-1.5 cm wide, ovate- lanceolate, rarely broadly ovate, acute, puberulus. Flowers drooping, turning purple-pink after anthesis. Pedicel with ovary 1.8-2.3 cm long, fusiform, densely short-tomentose. Sepals white or pale yellow with reddish purple spots and lines towards the base. Dorsal sepal 4.5 cm long, 2-2.5 cm wide, ovate-elliptic or narrowly elliptic, acute or acuminate, pilose towards the base, curving forward. Synsepalum 4.5-5.2 cm long, 2.5-3 cm wide, elliptic, naviculiform, acuminate, bidentate, pilose towards the base. Petals 4.8-5.3 cm long, 1.5-1.8 cm wide, obliquely narrowly elliptic or ovate- elliptic, acuminate, glabrous towards apex, pilose towards the base, drooping, white or pale yellow, densely purple-red spotted towards the base. Lip 5.5-6.5 cm long, 4 cm wide, 2.5 cm high, calceiform, ovoid to elliptic in outline, shortly and narrowly clawed at the base, margins incurved and nearly meeting at the centre, shortly apiculate at the front, barbate-hairy inside, white or pale yellow with interior dark yellow streaks and purple-red spots which are more intense inside. Column c. 1 cm long, 0.2-0.3 cm wide, greenish white; staminode c . 1 cm long, 0.7-0.8 cm wide, ovate-sagittate, apex cuspidate, convex, with 2 obscure longitudinal ridges, purple-red or dark lilac with a white apex; stigma 0.7-0.9 by 0.6cm, narrowly oblong- cuneate, subacute, white or pale yellow.

DISTRIBUTION. Taiwan, in forest and open, damp places; 2500-3000 m altitude.

Cypripedium japonicum Thunb. var. formosanum (Hayata) Ying in Chinese Flowers 15: 33, pl. 1 (1975); Quart. Bull. Chin. For. 8: 141 (1975); Alpine P1. Taiwan in Col. 1: 70, pl. 93 (1 975); Col. Illus. Indig. Orch. Taiwan 1: 356, 442, pl. 52 (1977). Type: Taiwan, Oiwake, 7500ft, April 1916, B. Hayata s.n. (TI, holotype). Cypripedium formosanum Hayata, Icones Plant. Form. 6: 66, fig. 9 (1916);

Schlechter in Fedde, Repert. Spec. Nov., Beihefte 4: 81 (1919); Cheng, Formosan Orch. 62 (1 979).

C.japonicum sensu Hayata, Icones Plant. Form. 2: 136 ( 1 91 2); Lui and Su in Flora of Taiwan 5: 951 (1978) and Su, Native Orch. Taiwan 171 (1985) non Thunb. (1 784).

75. SEDUM LUCIDUM Crassulaceae

David Hunt

Sedum lucidum R.T. Clausen, one of several large-leaved stone-crops native to Mexico (sect. Pachysedum A. Berger), has a restricted geographical range at the eastern end of the Trans-Mexican Volcanic Belt, being confined, so far as known, to the upper valley of the Rio Blanco, state ofveracruz, close to the border with Puebla. It is similar

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