Erect annual or perennial herb, simple or branched, 0.8–3 m. high, malodorous. Leaves subsessile or shortly petiolate; lamina cultrate, narrowly oblong, narrowly elliptic or oblanceolate, 2–11 x 0.4–4 cm., margins entire, more or less involute cuneate at the base, truncate, retuse or rarely acute, and usually mucronate at the apex, inferior surface white tomentose. Flowers reddish, pink, or pale mauve with darker markings; calyx lobes narrowly lanceolate or narrowly ovate, 5–10 mm. long, about 2 mm. broad at the base, acute or acuminate at the apex, pubescent; corolla large, 3.5–7 cm. long, 2–3 cm. in diam. at the throat. Capsule narrowly oblong in lateral view, subquadrangular, 4-sulcate, 18–28 x 5–7 mm., rather densely pubescent, gradually narrowed into a flattened rather broad and short beak (TAB. 23 fig. A). Seeds with a double fringe, about 2 x 1.5 mm., faintly rugose on the flanks and faces (TAB. 24 figs. A1, A2).