Annual or perennial herbs, sometimes subshrubs. Hairs usually dense, glandular and/or eglandular, rarely 0. Lvs opposite, exstipulate. Infl. cymose, sometimes reduced to solitary fl.; bracts and sepals herbaceous or with narrow to wide scarious margins; epicalyx 0. Sepals 5, free. Petals 5, white, emarginate or 2-fid up to ⅓ way, rarely 0; coronal scales 0. Stamens usually 10, sometimes 8, 5 or fewer. Styles (3)-5-(6). Fr. a cylindric capsule, often curved, dehiscing by twice as many short apical teeth as the styles, sessile. Seeds many, obovoid, spherical or reniform, tuberculate, not winged.