Leaf MorphologyLeaf Morphology

What Is Leaf MorphologyWhat Is Leaf Morphology

Leaf Morphology is the study of the external feature of leaves. It is useful for classification.

THREE TYPES OF THREE TYPES OF LEAVESLEAVESCotyledons are significant parts of the embryo within the seed of a plant .

Foliage leaves perform important functions: photosynthesis, respiration and transpiration.

Bracts (floral leaves) are found at the bases of flowers and are sometimes mistaken as petals. The poinsettia ‘flower’ is really composed of bracts.

In the following slides we will deal with foliage leaves only.

Leaf Leaf

is lateral outgrowth on the stem of a vascular plant.is an plant organ specialized for photosynthesis, respiration

and transpiration.

Leaf Morphology - Basic TermsLeaf Morphology - Basic Terms

Chart illustrating leaf morphology Chart illustrating leaf morphology

Types of Leaf Venation Types of Leaf Venation

There are two principal types of venation: Parallel-veined leaves(occur most often on monocotyledonous plants)

Reticulate-veined leaves, also called net-veined, have veins whose branch from the main midrib and then subdivide into finer veinlets.

Net venation may be

pinnate

palmate

Divisions of the BladeDivisions of the Blade

Simple leaves are those in which the leaf blade is a single continuous unit.

A compound leaf is composed of several separate leaflets arising from the same petiole.

Alternate leaves Alternate leaves - one leaf attached per node- one leaf attached per node

Opposite leaves Opposite leaves - two leaves attached per node- two leaves attached per node

Whorled leaves Whorled leaves – three or more leaves attached per node– three or more leaves attached per node

Leaf Arrangement on a StemLeaf Arrangement on a Stem

Economic Importance of LeavesEconomic Importance of Leaves

Edible leaves – cabbage, lettuce, spinachSpaces – basil, laurel, origanMedicine – thyme, datura, comfreyIndustry – sisal, woad (Isatis tinctoria) Fodder plants – clover, grasses

RESOURCESRESOURCESInternet:

http://www.celysvet.cz/pokojove-rostliny-rostliny-z-ozdobnymi-listy.php

http://ag.arizona.edu/pubs/garden/mg/botany/index.html

http://www.ag.auburn.edu/hort/amywright/hort3000/news.htmLiterature:

Lubomír Kincl: Biologie-rostliny

Thanks for your attentionThanks for your attention

David Hrabe