A leaflet in botany is a part of a compound leaf. A leaflet may resemble an entire leaf, but it isn't 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. A tomato plant has leaflets on compound leaves. 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 pinnul… (More on Leaflet)