Twiners woody or herbaceous. Leaves petiolate, ovate to circular, abaxially spotted with minute glands, as black dots in dried specimens, base usually cordate, margin entire. Cymes axillary, 1- to many flowered, peduncled; bracts early deciduous, small. Sepals ovate to elliptic or circular, equal or slightly unequal, much enlarged in fruit, ± leathery, abaxially glandular punctate, margin membranous, apex obtuse to emarginate. Corolla funnelform, midpetaline bands ± pilose and with minute glands. Stamens and pistil included; filaments filiform, inserted near corolla base; pollen globular, pantoporate, finely spiny. Disc ring-like. Ovary glabrous, 4-loculed; ovules 1 per locule. Style 1; stigma 2-globular. Fruit enclosed by enlarged calyx, globose; pericarp thin, eroding irregularly between septa to produce a lanternlike effect. Seeds 4 or fewer, pubescent.

Approximately 12 species: Africa, Asia; one species in China.