Carolina fanwort, fanwort Cabombacaroliniana A. Gray
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.