Leaves come in many shapes and sizes. They perform important functions for the plant like photosynthesis. Leaves either have a single leaf blade and are simple, or a divided leaf blade and are compound. Compound leaves include pinnately compound where leaflets are arranged along the rachis, and palmately compound where leaflets radiate from the tip like fingers on a palm. Monocot leaves typically have parallel veins while dicot leaves have reticulate veins.