Annual or perennial herbs, erect to prostrate. Lvs alternate, entire to pinnately dissected. Fls usually in cymes, sometimes in a dense head, sometimes solitary and axillary, sessile or pedicellate. Calyx herbaceous or occasionally with chartaceous marginal membrane below sinuses forming a projecting fold beneath each sinus at fruiting. Corolla narrow-funnelform or trumpet-shaped; tube slender; lobes spathulate to lanceolate. Stamens equally or unequally inserted on corolla throat, exserted or included. Style exserted or included. Capsule ellipsoid or obovoid, 2-locular, 2-lobed. Seeds 1-2 in each loculus, oblong, ± mucilaginous when wet.