Herbs, annual or perennial, monoecious. Stems somewhat succulent. Raphides present. Leaves petiolate, somewhat succulent, lower ones opposite, upper ones apparently alternate due to anisophylly, entire; stipules interpetiolar, membranous, united at base to petioles. Flowers unisexual, rarely bisexual, axillary in upper nodes, small 1-3 flowered cymes, bracts reduced. Staminate flowers sessile; calyx limb reduced; perianth (equivalent to corolla) deeply lobed, lobes 2-5, valvate, spreading or reflexed at anthesis, 3-5 parallel nerves; stamens (2-)6-30, sometimes united basally in groups, anthers linear, dorsifixed at anthesis, free slender filaments, pistillode reduced. Pistillate flowers subsessile; calyx limb reduced; perianth (equivalent to corolla) tubular, oblique, upper part an elongate constricted mouth, 2-4 denticulate-lobed; staminodes reduced; ovary 1-celled; style simple, exserted; ovule solitary, basal. Fruit a nutlike drupe, compressed; seed U-shaped; endosperm fleshy.