Duckweed
The family contains four to six genera (depending on the taxonomist) and is believed to be descended from Araceae.
Duckweed, also known as water lentil, is the smallest flowering plant in the world. The plant consists of a short stem floating vertically in the water, roots in Spirodela and Lemna, and occasionally a flower consisting of two stamens and a pistil (some call it an inflorescence consisting of three unisexual flowers). The fruit is a utricle, a sac containing air and a seed designed to float; that of Wolffia is the smallest in the world, 0.3 mm long. Reproduction is usually by budding (as in yeast; in flowering plants, such structures are usually called runners).
Duckweed
Scientific classification
Kingdom: Plantae
Division: Magnoliophyta
Class: Liliopsida
Order: Arales
Family: Lemnaceae Genera