European frog-bit
Native to: Europe and northern Asia
While not currently present in Florida, European frog-bit has escaped cultivation and become invasive in shallow slow-moving waters of eastern Canada and parts of the northeastern United States. It has also been documented in Washington State. Its first recorded North American introduction was to Canada in 1932 for an aquatic pond in the arboretum of the Central Experimental Farm in Ottawa. It may be confused with the native Frog’s bit (Limnobium spongia).
Family: Hydrocharitaceae
Habit: Perennial, free-floating aquatic herb
Leaves: Usually floating, kidney shaped with long stems, dark purple below, resemble tiny water lilies, 1-6 cm (0.5-2.25 in) across.
Flowers: White, cup-shaped, three-petaled with yellow dots at the base.
Fruit: Globose berry
Distribution in Florida: Not present
Spreads primarily vegetatively via long stolons and turions (winter buds that are produced on the stolons). In fall, turions drop off and remain dormant until spring when they begin to grow; one plant can produce over 100 turions a year. It forms dense floating mats of interlocking plants which cause negative environmental and economic impacts including displacing native species, reducing water quality and flow, clogging irrigation systems and impeding recreation.
Always clean boats and recreational equipment before leaving a waterbody.
Water drawdowns can help reduce populations. Hand pull small infestations in spring or summer after turions have germinated but before new ones drop.
Harvest in spring or summer after turions have germinated but before new ones drop.
Grass carp will feed on it.
Susceptible to the herbicides diquat, Paraquat™, chlorthiamid, and cyanatryn. Licensed professionals should be consulted before attempting chemical control in waterways.
