Trees or shrubs, sometimes scandent; leaves opposite or alternate, simple, entire, penninerved; stipules usually present, large, interpetiolar, sometimes connate; flowers perfect, small, irregular, 2-bracteolate, racemose or paniculate; sepals 5, free or connate at the base, subequal, imbricate, deciduous; petals 3 or 5, white or pink, free, subperigynous, alternate with the sepals, unequal and somewhat papilionaceous, contorted in bud; stamens 5-12, with 2-6 of the fertile ones united, the tube cleft on one side; filaments filiform, the anthers 4-celled, oval, opening by longitudinal introrse slits; disk sometimes present; ovary free, 3-celled; style terminal, simple, the stigma capitate or obliquely truncate; ovules 2 or more in each cell, 2-seriate, attached to a central placenta, anatropous; fruit capsular, 3-celled, septicidally 3-valvate, the valves separating from the central column and themselves often separating into endocarp and epicarp; seeds 2 or more in each cell, the testa thin, covered with long wool; endosperm carnose, the embryo straight, the cotyledons plane, the radicle short.Three genera, one in the Malay Peninsula, the others in tropical America. Only one is represented in North America.
TRIGONIA AubletUsually woody vines; leaves opposite, short-petiolate, generally whitetomentose beneath; stipules simple or bifid at the apex, deciduous; flowers small, in terminal panicles or compound racemes; sepals connate at the base, unequal, the 2 inner ones larger; petals very unequal, the posterior one largest, calcarate or saccate, pilose in the throat of the spur, the blade reflexed, the 2 anterior ones ascending, narrow, barbate above the base, the other 2 petals smaller, approximate, keel-like; stamens 10 but usually only 6 of them fertile; 2-4 hypogynous glands or a crenate crest present opposite the posterior petal; ovary attenuate to the style, hirsute, the stigma obliquely truncate; ovules several or numerous; capsule trigonous, usually pubescent outside and often also within; seeds several in each cell, compressed-globose. About 30 species, in tropical America. Two other Central American ones have been described from Nicaragua and Panama.Leaves mostly 4.5-8.5 cm. long, in age glabrous beneath or nearly so, with about 5 pairs of lateral nerves; capsule 2 cm. long or shorter; petioles 5 mm. long or shorter T. rasa.Leaves mostly 9-14 cm. long, usually abundantly pilose beneath even in age, with about 7 pairs of lateral nerves; capsule usually 2.5 cm. long; petioles mostly 7-13 mm. long T. floribunda.
