tropical to subtropical regions worldwide
Aeschynomene americana L.
A. evenia C. Wright
A. fluitans Peter
some species introduced into the United States
Some of the non-cultivated aquatic members of the genus are considered noxious weeds.
Annual or perennial. Stems erect, creeping or floating; emergent or seasonally submerged/floating stems often pithy and swollen when in water. Stipules usually persistent. Leaves alternate, compound (paripinnate), oblong; apex round to notched; base round to cordate. Leaflets numerous, usually opposite, subsessile; leaflet blade narrowly oblong; apex round; base round, asymmetric; margin entire to minutely toothed; venation palmate or prominent midrib. Inflorescence axillary or terminal, solitary flower. Flowers bisexual, zygomorphic; bracteoles present; calyx 2 lipped, upper lip 2-lobed, lower lip 3-lobed; posterior petal orbicular, lateral obovate-oblong, keel obovate or incurved, typically yellow. Pods transversely jointed, breaking apart at maturity.
riparian, wet to flooded soils
Aeschynomene consists of 150 species, most of which are in Central and South America and Africa. About 70 species in the genus are aquatic.