Annual or perennial erect herbs or rarely under-shrubs. Stem and branches ±
circular or obtusely quadrangular. Leaves sessile, linear or filiform, rarely linear-lanceolate; 1-nerved or sometimes 3-5 nerved. Stipules 2-lobed or fimbriate, rarely entire. Inflorescence usually paniculate or corymbose, rarely a capitulum, or flowers in pairs, triads or even solitary. Bracts filiform, subulate or narrowly triangular. Flowers small, 4-rarely 5-memos. Calyx 4(-5)-Lobed, lobes equal, subulate, ovate-triangular or triangular, distant on the capsule. Corolla 4(-5)-lobed, lobes ovate-lanceolate, often mucronate-cuspidate. Corolla-tube narrowly cylindrical, upper portion dilated. Stamens included and inserted in the dilated portion of the corolla-tube; sometimes anther tips slightly exserted, dorsi- or basifixed. Ovary bilocular; ovules numerous, immersed in fleshy peltate placentas. Style included; stigma simple and cylindrical or bifid and filiform, always situated ± below the anthers. Capsule globose or ellipsoid, splitting at the apex. Seeds many, angular, usually not becoming shining when moistened.