Herbs, trees, shrubs or climbers. Lvs usually alternate, simple or variously compound, often 3-foliolate, 1-imparipinnate, 1-paripinnate, or 2-pinnate, sometimes tendrilous, reduced to spines, scales or phyllodes, or even 0, usually stipulate. Fls in racemes, spikes, fascicles, heads or solitary, either regular and then often unisexual, or zygomorphic and then usually ☿. Calyx usually 5-merous, regular or asymmetric with teeth variously reduced and united, imbricate or valvate in bud. Petals usually 5. Stamens mostly 10, numerous in Mimosoideae, free or united into a tube, often with one stamen remaining free and the tube split; anthers 1-2-locular. Ovary usually 1-locular, rarely transversely septate; style usually long with terminal stigma; ovules in 2 rows but appearing in 1 rank, anatropous or amphitropous, ascending or pendent. Fr. typically a pod dehiscing by both sutures, but sometimes by one suture or indehiscent, usually dry or sometimes fleshy, straight, curved or spirally coiled, sometimes lomentaceous; seeds often strophiolate.