, typically organs associated with vascular plants.

The 'leaves' of , that is, are technically not considered to be leaves but instead represent modified .

This distinction in part has to do with leaves possessing vascular tissue (i.e., ) where movement of substances within nonvascular plants is largely a consequence instead of . Related to this issue, leaves literally are organs, meaning that they are composed of multiple tissues (such as vascular tissue), whereas the parts of nonvascular plants are not in the same way into separate tissues and thus don't possess distinct organs.

Specialized leaves that are optimized for purposes other than photosynthesis abound, such as the of . The of flowers also are specialized leaves. The and other -gathering organs of conifers, on the other hand, are leaves and are specialized for photosynthesizing.

Contrast leaves with stems as well as roots.