Vine or slender liana; stems with a prominent interpetiolar ridge, the younger stems sparsely puberulent, the older stems lenticellate. Leaves opposite; petioles 0.3-1 cm long, sometimes bearing triangular glands; blades elliptic, acute to acuminate, acute to obtuse at base, 5-10 cm long, 1.5-3.5 cm wide, glabrous above, glabrous to weakly short-pubescent below. Racemes simple, axillary, most parts inconspicuously short-puberulent; pedicels 3-8 mm long; bracteoles minute; flowers 5-parted; calyx lobes triangular, 1.5-2.3 mm long, with a single lacerate squamella inside; corolla salverform, greenish-yellow, with 5 epistaminal appendages deeply included and minute, the tube ca 1.5 cm long, the lobes obliquely obovate, 5-6 mm long; stamens barely exserted; anthers ca 4 mm long, glabrous, connate and glued to stigma; stigma l; nectaries joined at base, about as high as ovary. Follicles not seen, no doubt paired, terete, and slender as in other Prestonia. Croat 4401, Woodworth & Vestal 498(F). Collected recently, only at the Lighthouse Clearing. Seasonal behavior uncertain. Elsewhere in Panama, flowers from November to March. Panama to South America. In Panama, known from tropical moist forest in the Canal Zone and Panama, from premontane moist forest in the Canal Zone, and from premontane rain forest in Darién (Cerro Pirre).