Urticaceae
蕁麻科
特徵描述
作者
YANG, YUEN-PO, SHIH, BING-LING and LIU, HO-YIH
型態特徵
Monoecious, dioecious or rarely polygamous herbs, shrubs, or trees, with or without stinging hairs; cystoliths usually present in epidermal cells. Leaves alternate or opposite, sometimes anisophyllous with nanophylls (reduced leaves), petiolate or sessile, usually stipulate. Inflorescences often cymose glomerules, or sessile and condensed cymes in leaf axils, sometimes a head or a single flower. Flowers minute, unisexual or rarely bisexual, actinomorphic or zygomorphic, mostly green; perianth a single whorl or rarely absent. Male flowers: perianth segments 2-5, mostly free or connate in lower half; stamens 2-5, inflexed in bud, anthers basifixed, longitudinally dehiscent, rudimentary ovary often present. Female flowers: perianth segments 2-5, free or somewhat completely connate; staminodes present or absent; ovary superior, 1-loculed, stigma capitate, penicillate, ligulate or filiform; ovule 1, basal. Fruit an achene or drupe, sometimes enclosed by persistent perianth; seed with thin testa; embryo straight, surrounded by oily endosperm.
屬
About 45 genera with about 1,000 species, widely distributed in the tropical and temperate regions; 21 genera in Taiwan.
