Perennial herbs or shrubs, twining or prostrate, rarely erect. Leaves entire or lobed, 3-7-nerved with a usually dilated petiole, exstipulate but often with an undeveloped axillary stipule-like leaf (pseudostipule). Inflorescence solitary, axillary or in short fascicled racemes. Perianth zygomorphic or actinomorphic, coloured, tubular, tube inflated below, hairy inside, limb oblique, (1-)2 (-3)-lipped. Stamens (5-) 6 or multiples of these with sessile anthers. Ovary 5-6-celled; placentation parietal or axile; ovules many, anatropous, biseriate; style divided into 3,5 or 6 linear or obtuse lobes. Seeds ± compressed, usually winged all around.