LEAF TYPE

LEAF TYPEthe pattern of division of a leaf into discrete components or segmentsCan be either:1. Simple2. Compound

Simpleone bearing a single, continuous blade

Compound leafone divided into two or more, discrete leafletsare defined based on the number and arrangement of leaflets

LEAF DIVISIONSA simple leaf maybe highly divided, but as long as the divisions are not discrete leaflets, it is still technically a simple leaf

Leaf TypesPinnately compound / Pinnate leafBipinnately compound / Bipinnate leafTripinnately Compound / Tripinnate leafPalmately Compound / Palmate leafCostapalmate leafTrifoliate /Ternately compound leafBiternately compound leafGeminate leafUnifoliate

Pinnately Compound / Pinnate Leafone with leaflets arranged (either oppositely or alternately) along a central axis, the rachis

Pinnately Compound / Pinnate LeafIMPARIPINNATE- if a pinnate leaf has a terminal blade and typically an odd number of leafletsPARIPINNATE- if it lacks a terminal leaflet and has an even number of leaflets

Bipinnately Compound / Bipinnate Leafis with two orders of axes, each of which is pinnate (equivalent to a compound leaf of compound leavesthe central axis of a bipinnate leaf is still termed the rachisthe lateral axes that bears leaflets are termed rachillae (singular rachilla)

Tripinnately Compound / Tripinnate LeafCompound leaf with three orders of axes, each pinnate

Palmately Compound / Palmate Leafa compound leaf in which four or more leaflets arise from a common point, typically at the end of the petiole

Costapalmate Leafone that is essentially palmately compound to divided, but has elongate, rachislike extension of the petiole ( the costa) as occurs in some palms

Trifoliate / Ternately Compound Leafwith only three leafletsmost are palmate-ternate, in which the three leaflets join at a common pointrarely, ternately compound leaves can be pinnate-ternate, in which the terminal leafleat arises from the tip of the rachis

Biternately Compound Leafa leaf with two orders of axes, each ternately compound

Geminate LeafConsisting of only two leaflets

Bigeminate Leafa compound leaf with two rachillae, each bearing two leaflets

Geminate-Pinnate Leafa compound leaf with two rachillae, each of these bearing a pinnate arrangement of leaflets

Unifoliate Leafa very specialized type of leaf that appears superficially to be simple, but actually consists of a single leaflet attached to the apex of a petiole, the junction between them clearly definedis interpreted as being derived by reduction of an ancestrally compound leaf

Heteroblasty / Heteroblastic Leafin which the juvenile leaves are distinctly different in size or shape from the adult leaves