Cabomba is a genus of perennial, rhizomatous aquatic herbs in the family Cabombaceae, placed within the order Nymphaeales — one of the earliest-diverging lineages of flowering plants. The genus comprises six living species native to tropical and subtropical America, with the greatest diversity centred in Brazil.
Plants grow submerged in still or slow-moving freshwater, anchored by rhizomes. Their most distinctive feature is their finely divided, fan-shaped submerged leaves, which give rise to the common name fanwort. Small, emergent floating leaves are also produced. Flowers are small and white, pink, or purple, held just above the water surface, and are pollinated by flies and bees. Cabomba occurs naturally in ponds, floodplains, swamps, and creeks.
The genus was first published by Jean Baptiste Christophore Fusée Aublet in 1775; the type species is Cabomba aquatica. Three species are well known in cultivation: C. caroliniana (green cabomba), C. furcata (red cabomba), and C. aquatica. All three are widely used in the aquarium trade as ornamental and oxygenating plants.
The aquarium trade has also made Cabomba a significant global weed. Cabomba caroliniana escaped from aquaria in Australia after 1967 and is now a nationally declared weed, choking waterways along the eastern side of the continent and threatening water supplies. Cabomba furcata has similarly become invasive in Kerala (India), Sri Lanka, Malaysia, and Taiwan.
Etymology
The generic name Cabomba is believed to derive from an aboriginal name for the plant used in Guyana, though the exact source language is uncertain. The common name fanwort refers to the characteristic fan-shaped, finely divided submerged leaves.
Distribution
Cabomba is native to tropical and subtropical America, with its greatest diversity in Brazil. Through the aquarium trade, several species have been introduced far beyond this range: C. caroliniana is established across eastern Australia (declared a noxious weed nationally), and C. furcata has become invasive in Kerala (India), the Kalutara district of Sri Lanka, Chini Lake (Malaysia), and Taiwan.
Ecology
Cabomba inhabits still or slow-moving freshwater bodies — ponds, floodplains, swamps, and creeks. Flowers are pollinated by flies and bees. Where it has been introduced, the genus can outcompete native aquatic plants, degrade water quality, reduce biodiversity, and impede water flow.
Cultivation
Cabomba species, particularly C. caroliniana (green cabomba) and C. furcata (red cabomba), are popular aquarium plants valued for their feathery, fan-shaped leaves and their role as oxygenators in fish tanks. They are widely available in the aquarium trade. Due to their invasive potential, many jurisdictions prohibit their sale or import; growers should check local regulations before cultivating them outdoors or releasing them into any waterway.
Taxonomy Notes
The genus Cabomba was published by Aublet in 1775, with Cabomba aquatica as the type species. It is placed in the family Cabombaceae (alongside the monotypic Brasenia), within the order Nymphaeales — an ancient, early-diverging angiosperm lineage. Six extant species are currently recognised, plus four fossil species known from the palaeobotanical record.
