Fanwort

Cabomba caroliniana

Overview

Photo credit: ©RPS group Plc.
Cabomba caroliniana
Common names:
  • Fanwort
  • Cabomba
  • Carolina water shield
  • Carolina fanwort

Habitat:
  • Stagnant and slow flowing freshwater systems.

Description:
  • Fanwort is fully submerged except for occasional floating leaves and emergent flowers. The roots grow on the bottom of water bodies and the stems can reach the surface. It is a perennial, growing from short rhizomes with fibrous roots. The branched stems can grow up to 10m long and are scattered with white or reddish-brown hairs. The underwater leaves are divided into fine branches, resulting in a feathery fan-like appearance. These leaves are about 5cm across and secrete a gelatinous mucus which covers the submerged parts of the plant. The floating leaves, however, are small, diamond-shaped, entire, and borne on the flowering branches. The solitary flowers are less than 2cm across and range in colour from white to pale yellow and may also include a pink or purplish tinge. The flowers emerge on stalks from the tips of the stems.

Origin and Distribution:
  • Native to South America and also some southern states of the US.
  • The species is currently invasive in North America, Australasia-Pacific, Australia and Asia.
  • The species has also been recorded on sale in Britain.

Impacts:
  • This species can form dense stands that crowd out well-established plants.
  • Fanwort spreads primarily by stem fragments making control difficult if not impossible in some circumstance.
  • Where infestation rates are high, waterways can become clogged with ecological, recreational and economic consequences.
  • Drinking water can also become tainted by this species adding additional costs to treatment.

How might it get here?
  • This is a popular aquarium plant. Transport and inappropriate disposal of this plant is considered the most likely route into Ireland.

Is it found in Ireland or Northern Ireland?
  • It is not found in Ireland or Northern Ireland.

Risk assessments
Prevent Spread:
  • Promote native species and biodiversity - use alternative, native plants
  • Know what you are buying/growing and source native Irish seed and plants
  • Do not swap plants and cuttings
  • Clean plants before adding to ponds (dispose of water away from water courses)
  • Follow control advice and watch out for hitchhikers - inspect new imported purchases for invasive pest and pathogens
  • Clean equipment before moving between waterbodies
  • Never collect plants from the wild
  • Safe disposal of plant material and growing media
  • Report all sightings to CEDaR

Current Legislative Position (Listed on 03 August 2016)
  • This species must not intentionally be brought into the Union; kept; bred; transported to, from or within the United Kingdom, unless for the transportation to facilities in the context of eradication; placed on the market; used or exchanged; permitted to reproduce, grown or cultivated; or released into the environment. For further queries, you can contact the Non Native Invasive Species Team in the Northern Ireland Environment Agency on 028 9056 9558.

Species Related Files:

Invasive Species Ireland

Invasive Species Ireland