Perennial herbs with stems climbing or scrambling by means of long flexible and coiling shoots and petioles. Lvs alternate or opposite; lamina palmately veined, usually triangular to hastate or broadly ovate; margins dentate to crenate. Fls solitary and axillary. Calyx 5-lobed, ± irregular; lobes almost free or connate, often coloured. Corolla large, bilabiate, usually pink to purple or red, ± glandular-hairy; throat open, without inflated pouch; upper 2 lobes recurved; lower 3 lobes directed forwards. Stamens 4, included. Capsule globose or asymmetric, loculicidal with irregular apical dehiscence. Seed numerous, winged, tuberculate to appendaged, small.