Noun | 1. | ![]() common duckweed, Lemna minor, lesser duckweed - of temperate regions except eastern Asia and Australia Lemna trisulca, star-duckweed - cosmopolitan in temperate regions except North America great duckweed, Spirodela polyrrhiza, water flaxseed - cosmopolitan except South America and New Zealand and some oceanic islands watermeal - any of various aquatic plants of the genus Wolffia; throughout warmer regions of the world bogmat, mud midget, Wolffiella gladiata - having narrow flat sickle-shaped submerged fronds; North America aquatic plant, hydrophyte, hydrophytic plant, water plant - a plant that grows partly or wholly in water whether rooted in the mud, as a lotus, or floating without anchorage, as the water hyacinth |