Topic summary
Pinnate
Extracted from the Wikipedia article Pinnation.
Iteration of divisions
The term pinnula (plural: pinnulae) is the Latin diminutive of pinna (plural: pinnae); either as such or in the Anglicised form: pinnule, it is differently defined by various authorities. Some apply it to the leaflets of a pinna, especially the leaflets of bipinnate or tripinnate leaves. Others also or alternatively apply it to second or third order divisions of a bipinnate or tripinnate leaf. It is the ultimate free division (or leaflet) of a compound leaf, or a pinnate subdivision of a multipinnate leaf.