Anisotome is a genus of aromatic, tufted perennial herbs in the family Apiaceae (carrot family), order Apiales. The genus was established by Joseph Dalton Hooker in 1844 based on specimens collected during the Antarctic voyage of HMS Erebus and Terror, and is native primarily to New Zealand and its subantarctic islands, with a small presence in Tasmania and the broader subantarctic region.
The genus comprises small to large perennial herbs, sometimes rhizomatous, with a characteristic well-developed stock that is often multicipital and produced into a stout, deeply descending taproot. Plants are mostly glabrous or nearly so, and consistently aromatic due to copious latex. Leaves are typically pinnate, with yellow-green to dark green leaflets; rosette diameter ranges from 10 to 50 cm depending on species. The flowers are borne in usually compound umbels with many rays; petals are typically white, though occasionally pinkish to mauve or reddish, and are incurved. Calyx teeth are very small or obsolete. The fruit is usually narrowly oblong in outline, with distinctly compressed mericarps carrying five subequal, very narrowly winged ribs. Seeds are wind-dispersed via these winged mericarps.
Approximately 15 species are endemic to New Zealand, spanning habitats from coastal lowlands to alpine zones above 1700 m, including grassland, herbfield, cushionfield, scree-field, and rocky slopes. The most notable species include Anisotome latifolia, a striking subantarctic megaherb of Campbell Island and the Auckland Islands, and Anisotome aromatica (kopoti or common aniseed), which has the widest distribution across the North Island, South Island, and Stewart Island. GBIF recognises 27 accepted taxa in the genus. The Flora of New Zealand lists 15 indigenous species, all endemic.
Etymology
The name Anisotome derives from Greek roots meaning "unequal-sided," a reference to the asymmetric form of the fruit mericarps. The genus was described by Joseph Dalton Hooker in 1844 in Flora Antarctica, based on collections from Lord Auckland's Group and Campbell Island.
Distribution
Anisotome is distributed primarily across New Zealand — North Island, South Island, and Stewart Island — and extends to the subantarctic islands of New Zealand (including Campbell Island and the Auckland Islands). GBIF records also cover Tasmania and the broader Subantarctic region. All 15 species present in New Zealand are endemic to the country. Habitats range from coastal and lowland grassland to alpine herbfield, cushionfield, and scree above 1700 m elevation.
Ecology
Species in the genus occupy a wide elevational range from sea level to over 1700 m in alpine zones, occurring in grassland, herbfield, cushionfield, scree-field, and rocky habitats. Plants flower from October to February and fruit from November to April. Winged mericarps are wind-dispersed. Some species, notably Anisotome latifolia on Campbell Island, are considered subantarctic megaherbs, attaining large stature under the cloud-rich, humid subantarctic conditions.
