Star duckweed

''Lemna trisulca'' L. Schur; star duckweed; ivy-leaved duckweed) is a species of aquatic plants in the genus ''Lemna'' with a subcosmopolitan distribution, occurring in quiet, freshwater habitats in cool, temperate regions. ''L. trisulca'' normally does not occur in warm, temperate regions. Unlike other duckweeds, it has submerged rather than floating fronds, except when flowering or fruiting.