Description: Slender twining (occasionally trailing) annual herb, stems to 3 m, glabrous, thinly pilose with long white hairs or densely pubescent. Leaves petiolate, 2.5–8 × 1.5–6 cm, entire, ovate-deltoid or (very rarely) shallowly 3-lobed, narrowly cordate with rounded, entire or dentate auricles, apex shortly acuminate, mucronate, glabrous or thinly pilose on veins and margins or pubescent; petioles 0.5–5 cm, smooth. Inflorescence of axillary, pedunculate, umbelliform cymes, usually with 1–5(–9) flowers; peduncles 2–9 cm; bracteoles 5–7 mm, filiform, pilose, relatively persistent; pedicels 4–9 mm; sepals subequal, usually ciliate with stiff spreading hairs, occasionally glabrous, outer sepals 8–11 mm, ovate, gradually narrowed to an outwardly curved fine point, the central vein usually distinct, inner sepals 10–12 mm, obovate, abruptly or gradually narrowed to a mucronate apex; corolla (2.5–) 3.5–4.5 cm long, gradually widened from base, pink with a dark centre, glabrous, limb c. 2.5 cm diam., unlobed. Capsules subglobose, 7–8 mm, pilose; seeds brown, hemispherical, 3.5 mm long, glabrous.