Shrub or small tree, up to 4 m high, sparsely branched. Branches 0.3-0.5 cm in diam., terete, not winged; internodes 5-10 cm long. Leaves petiolate, arranged along stem; petiole 0.6-1.5 cm long; blade chartaceous, narrowly ovate to ovate-elliptic, 6.5-19 x 3-8.5 cm, margin flat, apex strongly acuminate, base attenuate. Flowers solitary, erect; calyx yellow to yellowish green, 26-40 x 7-11 mm, lobes ovate, 12-20 x 3-4 mm, margin membranaceous, apex long-acuminate; corolla yellow to yellowish green, tubular to funnel-shaped, 65-74 mm long, 7-12 mm wide at mouth, lobes ovate, 9-13 x 4-6 mm, apex acuminate, often dark green; stamens exserted from corolla mouth, filaments 40-50 mm long, straight, anthers yellow, elliptic, 3-4 mm long, slightly bent after anthesis; pollen exine reticulate; pistil 48-65 mm long, ovary 8-15 mm long, style 40-53 mm long, stigma lobe elliptic, 2-3 x 1-2 mm. Fruit erect, green when immature, brown when dry, ellipsoid, 22-25 x 5-6 mm; seeds not seen.
E Venezuela: present Guyana, Republic of: present present Pakaraima Mts: present
E Venezuela, Guyana (Pakaraima Mts.); 37 collections studied, of which 31 from Guyana (GU: 31).