Leaf Morphology

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

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