Description
Key Characters:
Growth Form:
Trees, shrubs, lianas, vines, or herbs.
Stems:
Roots:
Often bearing root nodules that harbor nitrogen fixing bacteria.
Leaves:
Leaves simple, unifoliate, or compound (palmate or trifoliate).
Alternate or rarely opposite.
Petioles and petiolules often with a basal pulvinus that governs its orientation, sometimes pulvinus present but not functional.
Stipules present, usually distinct, sometimes modified into spines. Leaflet stipels often present.
Flowers:
Flowers usually in racemes or panicles or in pseudoracemes (i.e. flowers in clusters on a shortened axis, these in racemose inflorescences), heads, or otherwise racemosely arranged inflorescences.
Flowers usually bisexual (perfect), unisexual in some species. Plants have flowers of one of the following flower types: caesalpinaceous (slightly zygomorphic, bracteoles present or absent, upper petal overlapped by others in bud, all petals usually spreading, stamens 10 or fewer, sometimes numerous, usually distinct), or papilionaceous [zygomorphic, bracteoles usually present, upper petal (standard) overlapping others in bud and spreading, with 2 lateral wing petals that cover and are often connate to the lower 2 keel petals, which are usually connate along their lower margin, stamens usually 10, distinct, or often 9 connate into a tube and 1 distinct or coherent, sometimes all connate], or mimosaceous (actinomorphic, bracteoles absent, petals valvate, distinct or connate, stamens 5 to numerous, distinct or connate).
Calyx 5-lobed, in some genera the upper 2 connate and hence Calyx appearing 4-lobed.
Corolla of (0–)5(6) petals; petals, usually distinct or variously connate.
Stamens few to numerous, usually 10, in a single whorl; filaments distinct or connate.
Ovary superior nearly always consisting of a solitary carpel, rarely 2 or more, superior, usually stipitate and fusiform, 1-celled or lomented, placentation parietal; ovules 1 to numerous, if 2 or more, then serially arranged along the placenta, if 1, then usually inserted near middle, campylotropous, anatropous, or hemitropous; style 1, apical; stigma simple or rarely 2 lobed.
Fruit:
Pods (legumes) usually dry; in a few genera drupaceous; often elastically dehiscent along both sutures or indehiscent; or breaking transversely into 1–seeded joints (articles); occasionally irregularly breaking up or samaroid.
Seeds 1 to numerous; seed coat usually hard; impervious; often with various sorts of valves to facilitate desiccation; such as horse–shoe–shaped pleurograms in Caesalpinioideae and Mimosoideae or a closed areole as in Senna; endosperm scanty or absent; embryo large.
Ploidy:
Habitat:
Elevation Range: