Cupaniopsis is a genus of approximately 45 species of flowering trees in the family Sapindaceae (order Sapindales), native to the southwestern Pacific and Australasia. The genus ranges across Australia, New Guinea, New Caledonia, Fiji, the Solomon Islands, Vanuatu, Samoa, the Torres Strait Islands, Indonesia, and Micronesia.
Trees in the genus are monoecious or dioecious and bear paripinnate leaves arranged alternately or in opposite pairs along the branches. The flowers are small and clustered in raceme-like or panicle-like inflorescences arising from the leaf axils. Each flower has 5 sepals, 5 petals, and 6 to 10 stamens, with an ovary typically containing 3 locules. The fruit is an oval to roughly spherical, slightly fleshy capsule; the seed is elliptical and enclosed in a thin, cup-shaped aril.
The genus was first formally described in 1879 by the Bavarian botanist Ludwig Adolph Timotheus Radlkofer, with Cupaniopsis anacardioides (tuckeroo or carrotwood) designated as the type species. A comprehensive 190-page monograph was published in 1991 by Dutch botanist Frits Adema, and Australian botanist Sally T. Reynolds contributed numerous formal descriptions and revisions between 1984 and 1991.
The best-known member, C. anacardioides, is a coastal tree widely planted as a street and amenity tree in Australia. It has also been introduced to the United States, where it is considered invasive in parts of Florida and Hawaii. Several Australian species have conservation listings: C. cooperorum (Cooper's puzzle) is listed as vulnerable in Queensland, C. serrata is endangered in New South Wales, and the New Caledonian endemic C. crassivalvis was assessed as globally extinct by the IUCN in 1998.
Etymology
The genus name Cupaniopsis means "a resemblance to Cupania," a related genus in the family Sapindaceae. Cupania was itself named in honour of Francesco Cupani, a 17th-century Italian monk and botanist.
Distribution
Cupaniopsis is distributed across Australia (primarily Queensland and New South Wales, with some species in the Northern Territory and Western Australia), New Guinea, New Caledonia, Fiji, the Solomon Islands, Vanuatu, Samoa, the Torres Strait Islands, Micronesia, and parts of Indonesia (including Sulawesi and the Maluku Islands). C. anacardioides has been introduced and naturalised in Florida and Hawaii, where it is regarded as an invasive species.
Conservation
Several species carry formal conservation listings. In Australia, C. shirleyana and C. tomentella are listed as vulnerable under the federal Environment Protection and Biodiversity Conservation Act 1999; C. cooperorum is listed as vulnerable and C. newmanii as near threatened under the Queensland Nature Conservation Act; C. serrata is listed as endangered in New South Wales under the Biodiversity Conservation Act. The New Caledonian endemic C. crassivalvis was assessed as globally extinct by the IUCN in its 1998 assessment.
