Herbs, dioecious, glabrous or mealy, with usually alternate, flat leaves. Male flowers 4-5-merous, in glomerules forming a dense spicate-paniculate inflorescence; stamens exserted; female flowers axillary, without perianth but with 2 (-4) persistent bracteoles which become enlarged, connate and hardened in fruit, stigmas 4-5, protruding; seeds vertical.