Leaf presence

The presence, absence or type of modification of the leaves on the plant.

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Leaves present and not modified

Leaves, apparently photosynthetic in function, are present, not modified to spines nor reduced to phyllodes or scales, or entirely absent.

Leaves present, but modified to phyllodes (expanded, leaf like petioles lacking a true leaf blade)

Leaves with the lamina much reduced or absent, the petiole (leaf stalk) and/or rachis performing the functions of the whole leaf. This condition is present in Ulex, and in Daviesia species, and is often (but not always) associated with vertical compression of the "leaf" and sub-parallel leaf venation. The flattened leaflet stems (phylloclades) of some species e.g. Jacksonia dilatata may be confused with phyllodes, but are recognised as phylloclades by the presence of flowers and fruits arising along their length.

Leaves present, but modified to spines

Leaves or phyllodes that are generally solid (flattened, terete or angular), stiffened, spiny pointed and usually linear/subulate in outline, a condition particularly common amongst species of Daviesia (e.g. Daviesia genistifolia). The short, spiny branchlets of some taxa (e.g. leafless Jacksonia) may be confused with spiny leaves, although the presence of a subtending leaf or leaf-scale indicates the nature of these organs.

Leaves mostly absent or reduced to scales

Members of several genera (e.g. Bossiaea, Daviesia, Jacksonia, Sphaerolobium, Templetonia) appear entirely leafless, have leaves that persist only during the juvenile phase, or have leaves that are deciduous prior to flowering. The stems of these taxa (generally referred to as "cladodes" or "phylloclades") may fulfill the primary photosynthetic function in the plant. A trait associated with this is the presence of minute leaf-scales (often brown in colour) or in Sphaerolobium, persistent leaf bases that subtend branchlets and inflorescence structures. For the purposes of this key, leaf scales are not considered equivalent (homologous) to leaves, and are not coded for leaf characters.