Fanwort - Invasive Species Information
What Is Fanwort - (Cabomba caroliniana)?
Habitat: Aquatic, Lakes, ponds and fast and slow flowing rivers
Distribution in Ireland: Sparse distribution but locally abundant in some places.
Family name: Cabombaceae
Reproduction: Fanwort reproduces
by both vegetative methods and
Vegetatively, - reproduces by
stem (rhizome) fragmentation.
Stems are very fragile, fragment easily and most pieces can re-sprout and grow into new plants
Seeds are also formed, and Fanwort can re-grow from seeds remaining in lake or pond sediment
Native to South America and southern parts of North America, Fanwort is a submerged invasive aquatic plant that can form dense mats at the water surface.
The delicate green underwater leaves are fan-like and average 5 cm across. Leaves are arranged in opposite pairs on the stem. Small oval floating leaves are occasionally present. Small diamond-shaped floating leaves with the stem attached in the center may develop. Tubular stems can attain lengths of 2m.
Why Is Fanwort A Problem?
Fanwort is a highly competitive plant that is capable of rapid growth and spread. It can displace native species, reduce biodiversity, hamper recreational uses, reduce real estate value, diminish aesthetic values, and decrease water quality.
Once established, Fanwort can negatively impact and out-compete native vegetation. Fish and animals that were dependent on the native vegetation must relocate or perish, leading to a decline
Fanwort can greatly impede boaters, fisherman, water skiers and swimmers, and these limitations on water use can negatively impact real estate values.
Fanwort produces dense large mats of vegetation on the water surface, thus intercepting sunlight to the exclusion of other submerged plants.
Sediment levels increase with increasing Fanwort abundance.
When dense mats of Fanwort decay, the available oxygen in the water may be depleted. The resulting low oxygen conditions (anoxic) can lead to fish kills and harm other aquatic organisms.
How To Identify Fanwort?
Colour: Tubular stems
Flowers: 1.5cm white or cream flowers form during May through September; Some variations of Fanwort have pinkish/purplish flowers
Size: Can grow up to 2 metres
Fanwort - Cabomba caroliniana ID Guide