Subshrubs, shrubs or trees (rarely herbs), glabrescent, pubescent, or hispid. Leaves petiolate, elliptic, lanceolate, ovate or cordate, sometimes lobed or dissected, margin dentate or less commonly subentire; abaxial foliar nectaries sometimes present. Flowers usually solitary (sometimes fasciculate) in leaf axils, often aggregated apically; pedicels long or short, (sometimes articulated). Epicalyx of 8-10(-20) distinct or basally connate bracts, simple or bifurcate. Calyx symmetrical, 5-lobed, red or green, sometimes inflated or enlarging with maturity, glabrate or pubescent, nectaries sometimes present, costae (if present) 3, one central and two marginal. Corolla yellow (sometimes with a purple spot at base), lavender, red, or other colours, sometimes large and showy. Staminal column included or exerted, apically 5 toothed, with numerous anthers. Styles 5, distally free with capitate stigmas. Fruit capsular, ovoid or oblong, 5-locular, glabrous or pubescent, dehiscent; seeds several in each locule.