作者

YANG, Yuen-Po

型態特徵

Fragile, mostly monoecious, submersed aquatic herbs, in fresh or brackish water. Stems slender, much branched, sometimes spiny. Leaves in pseudo whorls, narrowly linear, serrulate or serrate, sessile, sheathing at base. Sheaths with 2 axillary intravaginal scales, auriculate, truncate or decurrent, serrulate. Flowers minute, 1 or 2 in leaf axil, each often enclosed in a membranaceous spathe. Staminate flowers monandrous, in a spathe, subsessile or pedicellate; perianth segments hyaline, bifid at apex; anthers sessile, 1- or 4-celled. Pistillate flowers: ovary sessile, 1-celled, carpel 1; stigmas 2 or 3, unequally divided, persistent; ovule 1, erect from base of cell. Fruit oblong or ovoid, 1-seeded, usually embraced by leaf sheath. Seeds oblong or ovoid, with a conspicuous raphe, distinctly areolate; endosperm absent.

屬

One genus with about 50 species; cosmopolitan.

參考文獻