Aucuba is a genus of three to ten species of evergreen shrubs and small trees in the family Garryaceae (order Garryales), native to eastern Asia. The genus was formerly placed in its own family, Aucubaceae, or in Cornaceae, before molecular studies repositioned it alongside Garrya in Garryaceae.
Plants range from 2 to 13 metres tall and are recognisable by their glossy, leathery, opposite leaves — broad-lanceolate in shape, 8–25 cm long and 2–7 cm broad, with a few coarse teeth near the leaf apex. The foliage closely resembles that of true laurels (genus Laurus), and Aucuba species are commonly mislabelled as laurels in cultivation. All species are dioecious: male and female flowers are borne on separate plants. The flowers are small (4–8 mm across), purplish-brown, with four petals, and arranged in loose cymes of 10–30 blooms. The fruit is a red drupe approximately 1 cm in diameter.
The genus comprises three traditionally recognised species — Aucuba chinensis, A. himalaica, and A. japonica — though Flora of China and Plants of the World Online now accept up to ten species, with several additional taxa described from south-west China. The best-known member is Aucuba japonica, widely cultivated as an ornamental shrub in temperate gardens worldwide, especially its spotted-leaf cultivars.
Etymology
The genus name Aucuba is a latinization of the Japanese word Aokiba, the vernacular name for these plants in Japan.
Distribution
Aucuba species are native to eastern Asia, ranging from the eastern Himalayas through southern China, Taiwan, Korea, and Japan. Individual species occupy distinct ranges within this region: A. japonica occurs in Japan, Korea, and south-east China, while A. himalaica extends from the eastern Himalaya into southern China and northern Myanmar, and several species are endemic to south-west China (Yunnan).
Taxonomy Notes
Aucuba was historically placed in its own monotypic family Aucubaceae, and earlier still in Cornaceae. Molecular phylogenetic studies resulted in its transfer to Garryaceae (order Garryales), where it sits alongside the silk-tassel genus Garrya. Species delimitation within the genus is contested: three species were long accepted (A. chinensis, A. himalaica, A. japonica), but Flora of China and Plants of the World Online now recognise up to ten species.
Cultivation
Aucuba japonica is the most widely grown member of the genus, valued as a shade-tolerant ornamental shrub in temperate gardens. Its cultivars with yellow-spotted leaves (notably 'Variegata', commonly called gold-dust plant) are particularly popular. Because Aucuba is dioecious, both a male and a female plant must be present for the female to produce its ornamental red berries.
