Lemna L.
Infl. in a lateral pouch, partly enclosed in spathe. Ovules 1 or more. Seed us. ribbed and transversely striate; operculum prominent. Plants floating upon or beneath water surface, budding from lateral pouches, platelets solitary or many remaining attached together. Platelets mostly orbicular to obovate in outline, symmetric to asymmetric; nerve us. single. Root single, peltately attached. Some spp. pigmented red-purple. About 9 spp., the genus widespread.
