Donn. Sm., Bot. Gaz. (Crawfordsville) 27:435. 1899
Liana; stems minutely puberulent to papillate when young, becoming glabrate and conspicuously lenticellate. Leaves opposite; stipules inconspicuous; petioles slender, 1-6 mm long, canaliculate, puberulent; blades narrowly elliptic to oval, acute to acuminate at apex, broadly acute to obtuse or rounded at base, 4-12 cm long, 2-5.4 cm wide, the upper surface glabrous but with a usually puberulent midrib, the midrib bearing 2 acute glands near petiole, the lower surface glabrous, the midrib and major lateral veins villous and puberulent, the vein axils sometimes with inconspicuous pitlike domatia; reticulate veins not raised but easily visible. Inflorescences terminal, ± hemispherical; pedicels to 1 mm long; bracteoles narrowly acute, to 3 mm long; bracteoles, rachises, and calyces densely puberulent-papillate to puberulent; flowers white, to 5.5 mm wide; calyx lobes ovate, broadly acute to obtuse, ca 1 mm long, the squamellae inside minute, many; corolla lobed to about the middle, to ca 4 mm long, glabrous to very minutely papillate on outside, villosulous inside on tube, the lobes oblong-ovate, spreading at anthesis; stamens to ca 3 mm long, adhering to style; anthers ca 1.5 mm long, glabrous, exserted at anthesis; ovary ovoid, apocarpous, minutely papillate-puberulent, ca 3 mm long; stigma 1. Fruits unknown. Foster 4107.
Apparently rare, in the forest. Reportedly flowers only in February in Panama; flowers elsewhere in April and May.
Guatemala to Panama. In Panama, known only from tropical moist forest in the Canal Zone.