Sarmentose shrub, 1–3·5 m. high, or liana, 2·5–20 m. high, deciduous, flowers and leaves appearing at the same time; latex clear, white, or yellow. Roots thick and fleshy. Trunk up to 10 cm. in diam.; bark reddish-brown or grey-brown; branches scabrous as the result of persistent hair-bases; branchlets densely hispid. Leaves petiolate; petiole 1·5–5 mm. long; lamina dark green, paler beneath, ovate or elliptic, less often obovate or nearly circular, 1·1–2·3 times as long as wide, in mature leaves 8–23·5 x 5–16·5 cm. cuneate, rounded, or subcordate at the base, obtuse, acute, or acuminate at the apex (acumen 1–11 mm. long), papyraceous or chartaceous, in young leaves densely hispid on both sides, in older leaves glabrescent above, with 7–13 pairs of secondary veins; tertiary venation conspicuous beneath. Inflorescence 1–12-flowered, pedunculate, fairly congested, densely hispid in all parts; pedicels 3–14(20) mm. long; bracts sepal-like. Flowers fragrant. Sepals subequal, narrowly ovate or linear, 9–20(27) x 1·5–3·5 mm., acute, densely hispid. Corolla tube 13–24 mm. long and widening at almost 1/2-2/3 of its length into a cyathiform upper part, at the mouth (6)8–14 mm. wide, densely hispidulous outside except for the base, sparsely hispidulous inside except for the base; corona lobes Ungulate, 1–3 x 1–2·4 mm., minutely puberulous or papillose; corolla lobes ovate, 3–16 x 4–8·5 mm., gradually or fairly abruptly narrowing into the pendulous tails; lobes (including the tails) 100–160(–200) mm. long, puberulous except for the inner side of the tails. Stamens included for 2·7–7·3 mm.; filaments curved, 0·6–1·2(2) mm. high; anthers 3·7–6·2 x 0·6–1·1 mm., glabrous; acumen 0·1–0·5 mm. long. Ovary 0·8–1·7 x 1·5–2·3 mm., densely hispid with long erect hairs, sometimes glabrous at the base; style 6·5–13·5 mm. long; clavuncula 1–1·8 x 0·9–1·3 mm.; stigma minute. Follicles divergent at an angle of 180°, long tapering toward the apex and ending in a small or large knob, rarely without knob and then with an obtuse apex, 15–47 cm. long and 1·3–2·6 cm. in diam.; exocarp thick and hard, densely hispid or pubescent in young fruits and glabrescent when maturing, especially on the adaxial side densely lenticellate. Seeds with the grain 11–21 x 2·5–4·5 x 1·5 mm., densely pubescent; rostrum glabrous for 20–57 mm. and bearing a coma for 20–42 mm.; coma 42–80 mm. long.