FAMILY--LEGUMINOSAE (FABACEAE)

Trees, shrubs or herbs, often trailing or twining, unarmed, rarely spiny; phyllotaxy spiral to distichous; leaves pinnate, digitate, simple or reduced to scales or replaced by phyllodes; stipules usually present at the base of the petiole, stipels occasional on petiolules; flowers solitary, racernose or paniculate, rarely umbellate, usually bisexual, regular or zygomorphic, 5-merous, hypogynous; bracts commonly supporting the flower, often caducous; calyx usually with 5 lobes, sepals or teeth, rarely 4 or 3 when joined, basally variously united into a tube; petals usually 5, free or somewhat conhate, equal or distinct; stamens usually 10 sometimes less than 10 or numerous, free or variously cormate, inserted with the petals at the rim of the receptacle; anthers 2-1ocular, usually opening by longitudinal slits, uniform or dimorphic; ovary almost always a single superior 2- to many-ovulate carpel, rarely lovulate; ovules attached to the adaxial suture; fruit nearly always a dry legume or pod, usually dehiscent into 2 valves, often dehiscent only along the upper suture or indehiscent, occasionally lomentaceous; seed usually with endosperm, often arillate and/or carunculate. 

650 genera and 18,000 species, extends in all terrestrial habitats from the equator to the edges of dry and cold deserts of the world. 

The versatility of the legumes enhances their great economic importance as a food or forage. They fix nitrogen, conserve soils and provide timber, fuel and important legume crops.

The recognition of I family or 3 families within the Leguminales may still be regarded as a matter of opinion, but in general the evidence seems to support the concept of a single family, as few genera are transitional between the 3 major groups" as indicated in Polhill & Raven (1981), Advances in legume systematics pt 1. Their concept is accepted here and their systematic treatment followed.

1. Flowers regular (actinomorphic); stamens usually numerous; petals
       valvate, equal; embryo straight ............... ..............           Subfamily 2. MIMOSOIDEAE

   1. Flowers irregular (zygomorphic); stamens 10 or fewer; petals imbri-
       cate; embryo straight or curved.
     2. Flowers slightly irregular; stamens 10 or fewer, free; petals sub- .,
     equal, free; adaxial petal overlapped by adjacent lateral petals,
          abaxial petals overlapping; embryo straight .................          Subfamily 1.
                                                                                 DEAE

     2. Flowers very irregular; stamens 10, often united; petals unequal,
     more or less united; adaxial petal (standard) outside the adjacent
     lateral petals (wings), abaxial petals (keel) valvate conduplicate,
     often cormate; embryo curved ............................                   Subfamily 3. PAPILIONOIDEAE

(Source: Maslin 1992, Flora of South Australia)