Erect or diffuse annual or perennial herbs, di- or trichotomously branched Leaves opposite, often small and narrow, sessile or petiolate; stipules mostly acute or acuminate sometimes setaceous, bristly or fimbriate. Inflorescence a dichotomous axillary or terminal panicle or cyme, rarely solitary or fasciculate. Flowers small, generally white or rose, 4-merous, sometimes heterostylous. Calyx-tube subglobose, or turbinate, teeth 4, persistent, mostly distant in fruit. Corolla-tube infundibuliform, rotate or funnel-shaped, throat mostly villose, rarely glabrous, lobes 4, obtuse, valvate. Stamens 4, inserted at the mouth of the corolla-tube, filaments short, anthers dorsifixed, generally exserted rarely included and situated below the stigma (in Flora area); pollen grains globose or ellipsoid, mostly 3-(-4-5) colporate. Ovary 2-loculed, ovules numerous in each locule on peltate placentas; style filiform, glabrous or hirsute; stigmas 2, linear, short and obtuse. Capsule generally membranous, circular, didymous or winged, globose, dehiscence loculicidal at the top or rarely its whole length, many-or sometimes few- seeded; seeds angular or subglobose, testa generally smooth, rarely undulate, minutely punctate, granulate or reticulate.