特徵描述
作者
YANG, Yuen-Po
型態特徵
Fresh water herbs, monoecious, minute, free-floating or submersed, with a flattened or globular thalloid plant body, each with 1 or more roots or rootless, usually reproducing vegetatively, fronds sometimes remaining in a group with several or many individuals of different generations all connected by stipes. New buds produced in pouches. Flowers unisexual, not always present. Inflorescence with 1 or 2 staminate flowers and 1 pistillate flower, in some species sometimes enclosed in a spathe with 1 to several flowers. Staminate flowers with 1 stamen; anthers 1- or 2-celled; filaments slender. Pistillate flower solitary, sessile; style and stigma simple. Fruit a utricle.
屬
Four genera with about 30 species, cosmopolitan. Three genera and five species in Taiwan.
參考文獻
Wolffia 無根萍屬
作者
YANG, Yuen-Po
型態特徵
Thalli floating, ovoid, less than 1 mm long, upper surface dark green or light green, lower surface convex, always paired, without vascular tissue, budding from one side. Inflorescence in cavity of upper surface, without spathe, each with 1 staminate and 1 pistillate flower. Staminate flower with 1 stamen, anther 1-celled. Pistillate flower consisting of an ovary with 1 ovule, style short. Fruit a globose utricle.
