Lemna

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Lemna is genus of free-floating aquatic plants from the family Araceae, often referred to as the duckweeds. It was formerly classified in the family Lemnaceae.

Lemna species grow as simple free-floating thalli on or just beneath the water surface. Most are small, not exceeding 5mm in length, except Lemna trisulca which is elongated and has a branched structure. Lemna thalli have a single root, which distingushes them from realted species Spirodela

The plants grow mainly by vegetative reproduction, two daughter plants bud off from the adult plant. This form of growth allows very rapid colonisation of new water. They can also reproduce sexually.

When Lemna invades a waterway, it can be removed mechanically or treated with herbicide.

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