Osmanthus is a genus of approximately 30 species of evergreen flowering plants in the olive family, Oleaceae (order Lamiales). The genus ranges from shrubs to medium-sized trees, typically 2–12 metres tall, and is most diverse in eastern Asia — including China, Japan, Korea, Southeast Asia, and the Himalayas — with a small number of species extending to the Caucasus, New Caledonia, and Sumatra.
The leaves are opposite, simple, and evergreen, with margins that may be entire, serrated, or coarsely toothed. Flowers are small (around 1 cm long), white, and tubular with a four-lobed corolla, borne in compact panicles; many species produce a remarkably intense fragrance. The fruit is a small, hard-skinned dark blue to purple drupe, 10–15 mm in diameter, containing a single seed.
Osmanthus fragrans (sweet osmanthus or sweet olive) is by far the best-known species and has been cultivated in China for millennia. Its flowers are widely used in East Asian cuisine and culture — as an ingredient in tea, wine, beer, and confectionery, and as a source of fragrance in perfumery. The genus also includes popular ornamental garden plants such as Osmanthus heterophyllus (holly osmanthus) and Osmanthus delavayi, valued for their dense, attractive foliage and sweetly scented flowers.
Etymology
The name Osmanthus is a compound of two Greek words: osma, meaning smell or fragrance, and anthos, meaning flower — a direct reference to the genus's characteristic and often powerful floral scent.
Distribution
The majority of Osmanthus species are native to eastern Asia, with the centre of diversity in China, and extending through Japan, Korea, Southeast Asia, and the Himalayas. A small number of species are found further afield in the Caucasus, New Caledonia, and Sumatra.
History
Osmanthus has been cultivated and celebrated in China since ancient times. The earliest written references date to the Warring States period, when the Classic of Mountains and Seas (Shanhai Jing) described osmanthus trees growing on Mount Zhaoyao by the western sea. The genus has remained deeply embedded in Chinese cultural life, poetry, and cuisine ever since.
Cultivation
Osmanthus species are popular shrubs and small trees in parks and gardens across the warm temperate zone, and several hybrids and cultivars have been developed. They flower on old wood and generally produce the best floral display when left unpruned; a hard-pruned plant may fail to flower for one to five or more years until new growth matures sufficiently. In Japan, Osmanthus fragrans var. aurantiacus (kin-mokusei), with deep golden flowers and an intense sweet fragrance, is a favourite garden shrub; a white-flowered variant (gin-mokusei) is also widely grown.
Cultural Uses
The flowers of Osmanthus fragrans are used throughout East Asia both for their scent and flavour, often described as evoking apricot and peach. In China, osmanthus flowers are combined with black or green tea to make osmanthus tea, and the flowers are used to flavour locally brewed beer in Liuzhou. Osmanthus wine, made by infusing whole flowers in huangjiu or rice wine, is traditionally consumed during the Mid-Autumn Festival. The city of Guilin, whose name translates as "Forest of Sweet Osmanthus," has a particularly close cultural association with the plant. Commercial products flavoured with osmanthus include Pepsi for the Chinese market and White Rabbit milk candies.
