Carolina fanwort, fanwort
(Cabomba caroliniana A. Gray)

Overview

Appearance

Cabomba caroliniana is a perennial submersed aquatic plant that is native to the southeastern United States. It has become an invasive problem in parts of the United States where it is not native. It can grow in water 3-10 ft. (0.9-3 m) deep with stems up to 6.5 ft. (2 m) long.

Foliage

Cabomba caroliniana has two types of leaves. The submerged leaves are opposite, fan-shaped, deeply dissected and about 2 in. (5 cm) wide. The small floating leaves are entire and linear elliptic in shape.

Flowers

The flowers are long stemmed 1.2-4 in. (3-10 cm). They are most often white with yellow at the center, but may occasionally be pink or purplish. The sepals and petals are about 0.5 in. (1.25 cm) across. The petals are auriculate at the their bases, and obovate in shape.

Fruit

The fruit is flask shaped.

Ecological Threat

Cabomba caroliniana can form extremely dense stands which can clog drainage systems and interfere with recreational activities such as swimming and boating. It is still sold in the aquarium trade. It is believed the introduction of Cabomba caroliniana outside of its native range is a result of improper disposal of aquarium contents. The plants are able to root from vegetative parts and thus are easily spread. In the north it appears that the seeds do not readily germinate. However, viable shoots have been observed in January beneath ice.

Resources

• Weed of the Week - USDA Forest Service
• Global Invasive Species Database - Invasive Species Specialist Group
• Fact Sheet - Ontarios Invading Species Awareness Program

Selected Images

Maps

Invasive Listing Sources

• Alberta Fisheries Act
• California Noxious Weeds
• Connecticut Invasive Plant List
• Connecticut Invasive Plant Working Group
• Connecticut Noxious Weeds
• Idaho Noxious Weeds
• Maryland Aquatic Nuisance Species Plan
• Massachusetts Invasive Plants Advisory Group List
• Massachusetts Noxious Weeds
• Massachusetts Prohibited Plant List
• Michigan’s Prohibited and Restricted Species
• Mid-Atlantic Field Guide to Aquatic Invasive Species
• Minnesota DNR invasive species list
• National Park Service, Mid-Atlantic Exotic Plant Management Team Invasive Plant List
• Native Plant Society of Oregon, 2008
• New Hampshire Invasive Species Committee. 2005. Guide to Invasive Upland Plant Species in New Hampshire. New Hampshire Department of Agriculture,  Markets and Food Plant Industry Division and New Hampshire Invasive Species Committee.
• New Hampshire Prohibited Aquatic Species
• New Jersey Invasive Species Strike Team 2017 Invasive Species List
• New York Regulated and Prohibited Invasive Species - Prohibited
• Ontario’s Invading Species Awareness Program Tracked Species List
• Pacific Northwest Exotic Pest Plant Council, 1998
• Pennsylvania Department of Conservation and Natural Resources Invasive Plants
• Pennsylvania's Field Guide to Aquatic Invasive Species
• Rhode Island Natural History Survey
• To be proposed for MISC
• Vermont Noxious Weeds
• Washington Noxious Weeds
• Wisconsin Noxious Weeds
• Wisconsin's Invasive species rule – NR 40

References