Scientific name

Hydrocharis L.

Common names

frogbit, kilpukka, floating frogbit



Could be confused with

Hydrocleys, Limnobium, Limnocharis

Native distribution

Europe, Asia, Africa, Australia

Species commonly cultivated

Hydrocharis dubia (Blume) Backer (Asia, Africa, Australia)

H. morsus-ranae L. (Eurasia)

Adventive distribution

Hydrocharis morsus-ranae is introduced into New York, New England (United States), Quebec, and Ontario (Canada).

Weed status

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

Brief description

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.

Natural habitat

shallow waters of swamps, ponds, and lakes

Additional comments

Hydrocharis dubia is considered threatened in some regions of the world and weedy in others. Hydrocharis chevalieri (de Wildeman) Dandy is a mostly emergent, African species that is not presently cultivated.