Description from Flora of China
Herbs, mostly dioecious, monoecious in Flora area, with slender rhizomes. Leaves opposite; stipules small; leaf blade venation pinnate. Male inflorescence axillary, unbranched, flowers in clusters, usually widely spaced; pedicel very short. Male flowers: calyx lobes 3, valvate, closed in bud, membranous; petals absent; disk absent; stamens 8-20; filaments free; anthers 2-locular, anther-thecae pendulous, base distinct; pistillode absent. Female flowers axillary, solitary or in few-flowered spikes, sometimes with male flowers; sepals 3, imbricate; petals absent; disk segments 2, subulate; ovary 2-locular; styles 2, short, simple, free or basally connate, papillose. Fruit a capsule, 2-lobed. Seeds ovoid or globose, carunculate.
About eight species: Europe and Mediterranean Africa, temperate and subtropical regions in E Asia; one species in China.
(Authors: Qiu Huaxing (丘华兴 Chiu Hua-hsing, Kiu Hua-shing, Kiu Hua-xing); Michael G. Gilbert)