Leaves are often the most conspicuous part of any plant. Leaves vary tremendously in shape and in size: from the tiny leaves (less than 1 millimeter across) of the floating aquatic plant duckweed to the giant leaves (more than 10 meters in length) of the raffia palm. Nevertheless, all leaves share certain features of construction and development and carry out the same basic function: photosynthesis.

Leaf Types

Leaves are designed to optimize the capture of light for photosynthesis. In dicots, leaves typically have a broad, flattened blade attached to a stalk or petiole. The flat shape of the blade facilitates the penetration of light into the photosynthetic tissues within, while the petiole positions the blade so that it is shaded as little as possible by neighboring leaves. Leaf blades are referred to as simple when they are undivided and as compound when they are subdivided into individual leaflets. Compound leaves...