Amazon frogbit, American frogbit
Species commonly cultivated
Limnobium laevigatum (Willd.) Heine (Central and South America)
L. spongia (Bosc) Steud. (North America)
Limnobium laevigatum is introduced into the southern United States.
Sometimes considered troublesome. Limnobium laevigatum is a noxious weed in California (United States).
free-floating, stoloniferous rosette plant
Perennial, monoecious. Leaves floating or emergent, arranged in basal rosettes along stolons; petiole short or elongate; leaf blade orbicular-obovate to reniform, venation palmate, inconspicuous; base cordate to rounded; margin entire; aerenchyma on abaxial surface distinct; basal sheath present. Flowers unisexual, pedicels short, spathe of 1 or 2 free bracts; female flowers 1 to 3, hypanthium absent; males in cymes of up to 11 flowers; sepals 3; petals 3, rudimentary or absent in female flowers. Dispersal by seed and stem fragments.
still waters of lakes, rivers, ponds, and swamps