Stem twining, slender, with two puberulous lines. Leaves spreading; petiole 1/2–2 in. long; blade 1 1/2–6 in. long, 1–3 1/4 in. broad, oblong, ovate- or elliptic-cordate, acuminate, acute, or shortly and abruptly apiculate-cuspidate, glabrous, slightly pubescent along the midrib and nerves above and down the face of the petiole. Inflorescence sublateral at the nodes, 4–6 in. long, pedunculate, simple or branched, minutely pubescent, bearing several sessile clusters of small brownish-purple flowers racemosely scattered along it, 1/4– 3/4 in. distant; pedicels 2–3 lin. long, pubescent. Sepals 1/3– 1/2 lin. long, ovate, acute or subobtuse, puberulous. Corolla rotate, purplish, 1 1/2–2 lin. in diam., 5-lobed nearly to the base; lobes 3/4–1 lin. long, oblong, obtuse or subacute, glabrous. Coronal-tubercles transverse, arising near the base of the barely 1/2 lin. long staminal-column, dark coloured in the dried state. Follicles 2 1/2–3 1/2 in. long, lanceolate, acuminate, smooth and glabrous. Seeds 4 1/2 lin. long, 1 1/2 lin. broad, elongate-ovate, concave on one face, convex on the other, with a winged margin, toothed at the broad end, both sides with a minute tufted pubescence, light brown.