(H.B.K.) C. B. Robinson ex Small, N. Amer. Fl. 25:132.1910
B. cornifolia (H.B.K.) Spreng.
Liana; young stems, petioles, and blades below densely to sparsely pubescent, the trichomes appressed, T-shaped. Petioles 5-10 mm long, bearing 1 or 2 sessile glands along each side near apex; blades ovate to elliptic, acuminate (the acumen often downturned), rounded at base, 9-16 (18) cm long, 4.5-7 cm wide, glabrous and somewhat shiny and rugulose above. Panicles axillary or terminal, solitary or several per axil, 4-15 cm long, branched many times; peduncles, pedicels, and sepals densely pubescent, the trichomes short, appressed; peduncles to 3.5 cm long; pedicels sessile, to 1 cm long (to 1.5 cm long in fruit); sepals ovate, 2-3 mm long, bearing large exterior glands; petals clawed, 4-7 mm long, yellow, glabrous, caducous; stamens and styles glabrous; stamens unequal; anthers ± oblong, glandular; styles 3, distinct, ± equaling stamens. Fruits of 1-3 samaras, each samara with a single dorsal wing thickened along the inner side; seminiferous area ca 8 mm long, densely pubescent, raised, with a small wing or ridge on both sides; dorsal wing 2.5-3.5 cm long, ca 1 cm wide, bearing short appressed pubescence especially near seed and a small protrusion on inner margin just above seed. Foster 1478.
Rare, in the forest, usually growing in the canopy. Probably flowers in late rainy and early dry seasons, with the fruits maturing in the dry season.
Southern Mexico to Peru. In Panama, known from tropical moist forest on BCI and from premontane wet forest in Panama (Cerro Campana).