English: Duckweeds; Water lentils; Water lenses.
Clades:
Araceae;
Arales;
Aridae;
Lilianae;
Angiospermae;
Plants.
Members: Spirodela, Landoltia, Lemna, Wolffiella, Wolffia.
Regions: cosmopolitan; except the arctics
Habitats: still or very slow-moving freshwater environments, ponds, marshes, swamps, lakes, ditches, sluggish river backwaters; producing carpets on the water surfaces; prefer nutrient-rich (eutrophic) waters.
Content: dry-mass protein content up to 40%.
BotanyType: herbs; aquatic; small, very structurally reduced; very fast growing.
Root: highly simplified in Lemna; entirely absent in Wolffia and Wolffiella.
Stems: highly simplified; lacking wood; sparse, rudimentary veins.
Leaves: reduced, simplified, flattened; named frond or thallus; only a few cell layers thick; float due to air filled, aerenchyma, spongy tissue; in temperate climates producing modified, starch-heavy, fronds called turions, that sink to the bottom, to survive the winter and float back to the top in the spring; absorb nutrients like nitrogen and phosphorus directly through the underside of their fronds.
aquatics.org
Flowers: microscopic, reduced; infrequent, in less than 1% of generations; smallest flowers; 1 pistil; 1 or 2 stamens.
Reproduction: primarily asexual (clonal) budding.
DiffrentiationGenus Roots Per Frond Meristem Pouches Distinguishing Visual Feature
Spirodela 7 to 21 roots 2 Largest duckweeds; fronds often purple underneath.
Landoltia 2 to 5 roots 2 Intermediate size; often has dotted air chambers.
Lemna 1 single root 2 Classic "common duckweed" shape; flat oval fronds.
Wolffiella Rootless 1 Elongated, ribbon-like, or spindly fronds.
Wolffia Rootless 1 Globular/grain-like; smallest angiosperms on Earth.
TaxonomyFormerly,
Lemnoideae were classified in their own family, Lemnaceae.