Shrubs, subshrubs or herbs, erect, prostrate or twining, spinous or not. Leaves simple, alternate, entire or lobed, often pubescent. Flowers bracteate, in terminal or axillary cymes, involucrate heads or solitary. Sepals free, equal or subequal. Corolla usually campanulate. Filaments epipetalous, usually unequal, gradually subulate. Ovary 2-4-locular, style single, stigmas 2, filiform, linear, or cylindrical. Fruit a capsule, glabrous or pubescent. Seeds 1-4, smooth or tuberculate, glabrous or pubescent.