作者

YANG, Yuen-Po

型態特徵

Erect, glabrous, annual or perennial marsh or aquatic herbs. Leaves radical, linear, lanceolate, sagittate, broadly ellipsoid to deltoid, or reduced to phyllodes, petiole sheathing, elongate, nerves converging towards apex and connected by transverse veinlets. Inflorescences racemes or panicles, occasionally umbels. Flowers often whorled at nodes of inflorescence rachis, actinomorphic, unisexual, bisexual or polygamous, bracteate, pedicellate; sepals 3, green, persistent; petals 3, white, fugacious, or sometimes persistent; stamen 3-numerous, anthers 2-locular, extrorse; gynoecium of numerous free carpels in a single whorl or spirally arranged on receptacle; ovules 1-several per carpel; style persistent. Fruit a cluster or whorl of laterally compressed achenes; achene with a U-shaped embryo, endosperm absent.

屬

Ninety six species in 11 genera, cosmopolitan, especially abundant in the temperate and tropical regions of the northern hemisphere; three genera with five species in Taiwan.

參考文獻

• YANG, Yuen-Po, Flora of Taiwan, second edition 5: 4. 2000.  (Fl. Taiwan 2nd edit.)