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
Lemna 青萍屬
作者
YANG, Yuen-Po
型態特徵
Thallus floating or submersed, solitary, or many in groups or connected in long chains, orbicular or obovate, asymmetrical, green on both surfaces, mostly with 1 main vein and 1 lateral vein; root 1. Plants budding from two lateral pouches. Inflorescence with 2 staminate flowers and 1 pistillate flower, enclosed in a spathe; anthers 2-celled; ovary with 1-several ovules. Fruit 1-seeded. Seeds ribbed with transverse striations.
