Leaf

Tree leaves

A leaf is the main organ of photosynthesis and transpiration in plants. Leaves possess many shapes, sizes, functions and manners of being. Leaves of most woody trees and bushes consist of a flat blade connected to the woody stem or twig via a slender, stick-like petiole. The blade and the petiole make up the leaf. Hundreds, even thousands, of leaflets can occur in a single compound leaf. A poison ivy leaf consists of three leaflets. Most but not all leaves, even compound leaves, are shaped in such a way that they more or less display bilateral symmetry.

Leaves change colors during the fall season, making the fall foliage beautiful. This innate beauty, with no practical purpose other than to please humans, is one of the Counterexamples to Evolution.

## See also[edit]

* Walnut
* Evergreen tree
* Lime
* Simple Leaf