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Leaf Morphology
What Is Leaf Morphology
Leaf Morphology is the study of the external feature of
leaves. It is useful for classification.
THREE TYPES OF
LEAVES
Cotyledons 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
 is lateral outgrowth on the stem of a vascular plant.
 is an plant organ specialized for photosynthesis, respiration
and transpiration.
Leaf Morphology - Basic Terms
Chart illustrating leaf morphology
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 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.
Leaf Arrangement on a Stem
 Alternate leaves
- one leaf attached per node
 Opposite leaves
- two leaves attached per node
 Whorled leaves
– three or more leaves attached per node
Economic Importance of Leaves
 Edible leaves – cabbage, lettuce, spinach
 Spaces – basil, laurel, origan
 Medicine – thyme, datura, comfrey
 Industry – sisal, woad (Isatis tinctoria)
 Fodder plants – clover, grasses
RESOURCES
Internet:
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.htm
Literature:
Lubomír Kincl: Biologie-rostliny
Thanks for your attention
David Hrabe 