Trailing herb, about 1·5 m. long. Stems usually several from the base, procumbent, rather slender, glabrous or thinly hairy. Leaves deeply palmately to pedately 7–9 (11)-sect, 2–8 cm. in diam., glabrous above, thinly pubescent beneath; leaflets linear-oblong, narrowly oblong-lanceolate or spathulate-obovate, acute or obtuse, apiculate, tapering at base into the very short portion of the leaf by which they are connected, the lateral ones gradually smaller; petiole up to 5 cm. long. Inflorescence 1-flowered or occasionally cymosely 2–3 flowered; peduncle 5 mm. long; bracteoles linear or linear-lanceolate, acute, thinly pubescent; pedicels varying in length, at first erect or patent, ultimately reflexed. Calyx turbinate, 10–15 mm. long in flower, inflated in fruit; sepals unequal, ovate, subobtuse to acuminate, about 8 mm. long, concave, softly pubescent, with 6–7 purple-brown nerves deeply sulcate-plicate and with small purplish spots, hairy on the nerves, very accrescent in fruit, inner ones shorter and narrower, less concave, without or with only a few purplish stripes, not sulcate or plicate, hardly accrescent in fruit. Corolla widely funnel-shaped, 15–20 mm. long, yellow or whitish with a purplish centre; the limb shallowly 5-lobed to pentagonal, glabrous or thinly pubescent towards the base. Capsule completely enclosed by the inflated calyx, somewhat depressed. Seeds black, shiny, smooth, glabrous except for minute flattened hairs along the ciliate angles.
