Acronychia is a genus of approximately fifty species of shrubs and trees in the rue family Rutaceae, order Sapindales. The genus has a broad distribution spanning India, Malesia, Australia, and the islands of the western Pacific Ocean, with roughly twenty species endemic to Australia.
Plants in the genus are recognisable by their simple or trifoliate leaves, arranged in opposite pairs and dotted with oil glands — a characteristic feature of the Rutaceae. Flowers are borne singly or in cymes or panicles in the leaf axils and are bisexual, with four sepals, four free petals, and eight stamens. The stigma is small and not differentiated from the style; the fruit is a drupe bearing black seeds.
The genus was first formally described in 1775 by Johann Reinhold Forster and Georg Forster in their work Characteres Generum Plantarum. The type species is Acronychia laevis. Some species carry common names incorporating the word "aspen", a name also applied to unrelated Northern Hemisphere trees in the genus Populus (family Salicaceae).
Acronychia acidula, the lemon aspen, is perhaps the best-known member of the genus, having been promoted as an edible food plant. Several other species are cultivated in tropical and subtropical gardens across their native range.
Etymology
The genus name Acronychia was established in 1775 by Johann Reinhold Forster and Georg Forster in Characteres Generum Plantarum. Some species in the genus carry common names that include the word "aspen", a term otherwise associated with Populus trees of the Northern Hemisphere.
Distribution
Acronychia has a broad range across tropical and subtropical Asia and the Pacific, occurring in India, Malesia, Australia, and the islands of the western Pacific Ocean. Approximately twenty of the roughly fifty species are endemic to Australia.
Taxonomy Notes
The genus Acronychia belongs to the family Rutaceae (order Sapindales), a family characterised by aromatic oil glands in the leaves. It was first formally circumscribed by J. R. Forster and G. Forster in 1775, with Acronychia laevis designated as the type species. GBIF currently recognises 33 accepted taxa within the genus.
