LEAFLET

A 'leaflet' in botany is a part of a compound leaf. A leaflet may resemble an entire leaf, but it is not borne on a stem as a leaf is, but rather on a vein of the whole leaf. Compound leaves are common in many plant families.
Leaflets borne on the central vein of a leaf are referred to as ''pinnae''; the compound leaves themselves are described as ''pinnate''. A plant may be further subdivided in that the pinnae are themselves split into leaflets, or ''pinnules''; these leaves are now twice pinnate, or ''bipinnate''. A few plant species even have ''tripinnate'' leaves.