Herb 0.3–1.5 m. tall; stems usually single, mostly somewhat woody, glabrous to sparsely pubescent or densely hairy with short hairs. Leaves in whorls of 3–5 or rarely opposite; leaf-blades narrowly to broadly elliptic, elliptic-lanceolate, lanceolate or narrowly ovate, 3.9–13 cm. long, 0.9–5.6 cm. wide, subacute or rounded at the apex, rounded to cuneate at the base, glabrous to densely velvety; petiole obsolete; stipules with 1–5 ciliate setae, 0–5–8(–10) mm. long from a short base; often one deltoid lobe with a colleter on either side of it between the leaves in plants with 4–5 leaves in a whorl. Inflorescence consisting of 1 terminal and 2–4 axillary ones amalgamated, up to 12 cm. wide, each cluster with ± 30 flowers; peduncles 0–7.5 cm. long. Calyx glabrous to hairy; tube 2–5 mm. long, 2–4 mm. wide; lobes deltoid to filiform, 3–11 mm. long, 1–1.5 mm. wide at base, subulate at the apex, ciliate. Flowers white, sweet-scented. Corolla-tube 3–13 cm. long, 1.5–3.3 mm. wide at the base, scarcely dilated at the apex to 2.5–3.5 mm. wide for a distance of 1.2–1.7 cm., shortly hairy outside; throat densely hairy with long hairs; lobes sometimes yellowish, linear-oblong to elliptic-lanceolate, (0–5–)0.8–1(–1.8) cm. long, 1.5–4.5 mm. wide, acute, hairy outside. Stamens entirely included. Style exserted (0–)0.3–1.8 cm., densely tomentose with white papillae; stigma-lobes blackish, elliptic, 1–3 mm. long, thickened. Fruit obovoid-obtriangular, 1–1.5 cm. long, 0.7–1.1 cm. wide, prominently ribbed, pubescent; calyx-lobes reflexed, the limb-tube nervose, 3.5–4 mm. tall, exceeding the 2 mm. long beak. Seeds brown, ovoid, 1–1.5 mm. long, conspicuously reticulate.