(H.B.K.) Sandw., Lilloa 3:459. 1938
A. punctulatumPitt. & Standl.
Liana; stems glabrous or sparsely puberulent (especially at nodes), ± terete with interpetiolar ridges; tendrils simple, emerging from between leaflets; pseudostipules foliaceous, obovate, 3-13 mm long, to 10 mm wide, 4 per node. Leaves bifoliolate; petioles 0.7-3.4 cm long; petiolules 0.3-2 cm long; petioles and petiolules puberulent especially on upper surface; leaflets elliptic, acute to acuminate, acute at base and ending abruptly, 5-15 cm long, 1.7-7 cm wide, minutely lepidote. Flowers axillary, emerging from between pairs of pseudostipules; pedicels minutely bracteate, to l.5 cm long; calyx truncate, ca 1 cm long, with sunken plate-shaped glands near apex, fitting loosely around slender base of corolla tube; corolla 5-10 cm long, 3-4 cm wide at apex, pale yellow outside except for white lobes, papillose-puberulent on lobes inside, 2 lobes opposing the other 3, the lower 2 usually recurved, the tube expanded below lobes, glabrous except in basal third below point where filaments are fused to tube; nectar guides bright yellow, alternating with lobes; stamens included, the longer ones 2.3-3.1 cm long, the shorter ones 1.6-2.1 cm long, the thecae divaricate, 3.5-4.5 mm long; staminodium 3-6 mm long; pistil 5.1-5.6 cm long; ovary rounded-cylindric, to 2.5 mm long. Capsules ellipsoid, smooth, 5-15 cm long, 3-5 cm wide, stipitate at base; seeds oblong, to 1.8 cm long and 2.4 cm wide, with broad opaque wings. Croat 12683.
Uncommon; collected chiefly on the shoreline of Gigante Bay. Flowers irregularly through the year, especially during the rainy season, with one or two long-lived flowers open at a time. Most seeds are probably released in the dry season.
The species is easily recognized by its yellow flower and foliaceous pseudostipules. When open, the flowers have a very sweet, pleasant aroma. Corolla tubes are often pierced with a hole 3-4 mm diam just above the edge of the calyx by nectar-stealing insects or birds.
The seeds are water dispersed (Gentry, 1973b).
Belize to Venezuela. In Panama, known from swampy areas of tropical moist forest in the Canal Zone (Atlantic slope), Bocas del Toro, Colón, Panama, and Darien and from tropical wet forest in Colón, and Darien.