Herb, up to 1.6 m high, unbranched to sparsley branched. Stems and branches up to 0.7 cm in diam., terete to weakly quadrangular with or without small wings, wings 0.1-0.3 mm wide; internodes 0.5-17.4 cm long. Leaves sessile to shortly petiolate, evenly cauline with internode between 2 most apical sets of leaves visibly longer; petiole 0-0.4 cm long; blade membranaceous (coriaceous), linear, lanceolate or elliptic, 1-21 x 0.2-3.7 cm, margin not thickened, flat, apex acute to acuminate, base attenuate or cuneate. Inflorescence 1-60-flowered; bracts ovate to oblong, 1.2-5 mm long, apex obtuse (acute); pedicel 2-24 mm long. Flowers erect to horizontal; calyx green, 4-9 x 3-7 mm, lobes fused for ca. 4/5 of total length, ovate to circular, 2-6 x 2-5 mm, margin membranaceous, apex obtuse; corolla white, cream, green or greenish yellow, with dark green spot on apex of each corolla lobe, funnel-shaped to tubular, 21-52 mm long, 10-32 mm wide at mouth, lobes ovate or circular, 3-9 x 3-15 mm, apex obtuse (acute); stamens not exserted, filaments 17-35 mm long, mostly straight, curved downward close to anther, anthers white, elliptic to slightly obovate, 2.3-3.5 mm long, straight after anthesis; pollen exine differentially reticulated with globules (see Nilsson, 1970, 2002); pistil 29-32 mm long, ovary 3.2-4.3 x 1.9-2.4 mm, style 20-40 mm long, stigma lobes orbicular, 1.5-2.4 x 1.1-2.4 mm. Fruit erect to horizontal, brown, ellipsoid, 5-14 x 1-8 mm; seeds brown, 0.1-0.5 mm in diam.
Andes of Bolivia present, Brazilian Amazon present, Guianas present, Guyana present, Southern America: Brazil North (Acre present, Amazonas present, Roraima present); Colombia (Colombia present); Peru (Peru present); Venezuela (Venezuela present)
Colombia, Peru and Andes of Bolivia, Venezuela, Guyana, Brazilian Amazon (Acre, Amazonas, Roraima); 166 collections studied, of which 5 from the Guianas (GU: 5).