Syst. Veg. Fl. Peruv. Chil. 1: 169. 1798.
Herbs, annual [perennial], [shrubs, small trees, rarely lianescent], single-stemmed. Stems erect, sparsely pubescent. Leaves alternate; petiolate; uniform or dimorphic; blade surfaces pubescent. Inflorescences terminal, racemes; peduncle present; bracts deciduous. Pedicels present. Flowers greenish or cream, to blue-tinged in age or on drying, wings bluish purple [flowers dark blue to purple and keel distally yellow], chasmogamous and, sometimes, cleistogamous, (2–)2.5–3.5 mm; sepals deciduous, rarely subpersistent, glabrous; wings deciduous, rarely subpersistent, 1.5–3 mm, glabrous or proximally sparsely ciliate; keel entire, ± 3-lobed, glabrous; stamens 6[–8] in chasmogamous flowers, divided into 2 groups by central tuft of hairs, fewer in cleistogamous flowers; ovary 1-loculed [2-loculed], or appearing so. Fruits samaroid [drupes], indehiscent, margins winged, sparsely pubescent or glabrate. Seeds glabrous, not arillate.
sw United States, Mexico, Central America, South America.
Species ca. 180 (1 in the flora).