frogbit, kilpukka, floating frogbit
Europe, Asia, Africa, Australia
Species commonly cultivated
Hydrocharis dubia (Blume) Backer (Asia, Africa, Australia)
H. morsus-ranae L. (Eurasia)
Hydrocharis morsus-ranae is introduced into New York, New England (United States), Quebec, and Ontario (Canada).
Hydrocharis dubia is considered a weed in Japan, while H. morsus-ranae is a weed in the United States.
creeping, stoloniferous plant with floating and emergent leaves
Perennial, stoloniferous. Stolons creeping, originating from leaf axils. Stipules distinctive. Leaves floating or emergent, in rosettes widely spaced along stolon, petiolate; leaf blade ovate to orbicular, venation palmate with cross-veins; base cordate to reniform; margin entire; aerenchyma present at base of leaf. Inflorescence subtended by spathe of 1 or 2 bracts. Flowers unisexual; male flowers sessile, 1-4 per spathe; female flowers pedicellate, solitary; sepals 3; petals 3. Dispersal by seed and stem fragments.
shallow waters of swamps, ponds, and lakes