Annual or perennial, glabrous herbs or subshrubs, with monopodial or sympodial branching. Leaves alternate, opposite or whorled, simple, entire, often somewhat fleshy and crowded into a basal rosette and with pseudowhorls on stem; exstipulate or stipules membranous, sometimes laciniate; petiolate (sometimes weakly). Inflorescence mostly terminal or seemingly axillary cymes, sometimes few-flowered axillary fascicles or cymes, or solitary flowers; bracts and bracteoles minute. Flowers bisexual (rarely unisexual and dioecious), regular; sepals (4-)5, free, membranous; petals absent in Guianan species or few to numerous; stamens (3-)4-5(-numerous), filaments usually connate at base in short cupular tube, anthers 4-locular, dehiscing by longitudinal slits; ovary superior, (1-)2- to 5-locular, ovules 1-numerous per locule, placentation axile, anatropous to campylotropous, bitegmic, crassinucellate, styles or stigmas as many as locules, usually free. Fruit a loculicidally dehiscent capsule; seeds usually reniform, smooth, sometimes with a funicule and strophiole, embryo peripheral, curved, perisperm hard, starchy, endosperm scanty or absent.
Africa: Guianas: present New and Old World tropics and subtropics: present
Approximately 120 species in 13 genera, occurring mainly in the New and Old World tropics and subtropics, including a primary center of distribution in southern Africa; 2 genera in the Guianas.
MOLLUGINACEAE, Endress and Bittrich (1993) observed that "morphologically, the basic differences with the AIZOACEAE are in the structure of the androecium and the calyx, funicle length and the epidermis of leaves and stems." For additional information, see also note under family 30. AIZOACEAE.