Definition - What does Leaf mean?
A leaf is a usually green, flat lateral structure that protrudes from a plant's stem to collect sunlight for photosynthesis, and the site where transpiration takes place.
Leaves are an absolutely essential part of any vascular plant for the processes of transpiration and photosynthesis.
MaximumYield explains Leaf
Leaves have two main classifications: simple and compound. A simple leaf is a single, undivided leaflet while a compound leaf is comprised of multiple leaflets.
A leaf can also be petiolated or sessile in structure. A petiolated leaf is one that has a short stem to extend the leaf outward. A sessile leaf attaches directly to the stem without a petiole or stem.
All of a plant's major life functions occur as a result of leaves. A plant uses them to convert sunlight into energy during the process of photosynthesis and to discard excess moisture from the plant during transpiration, which is a process where moisture is released back into the atmosphere through evaporation from the leaf's surface.