Kumquat

Kumquat (Citrus japonica), also called round kumquat or fortunella, is an evergreen shrub or small tree of the citrus family (Rutaceae), 2–4 m tall, much branched, with small thorns on young shoots. Leaves are ovate, dark green, alternate, with small winged petioles; crushed leaves smell of essential oil. Flowers are small and white, fragrant, borne singly or in clusters in the leaf axils, usually self-pollinating. The fruit is small, 2–4 cm, round or oval, with a thin edible orange-yellow rind, sweet-sour, containing 3–6 segments and seeds. Unlike most citrus, kumquat is eaten whole including the rind, which is rich in aromatic essential oil. The species is native to southern China and East Asia and has long been grown in Vietnam.

In Vietnam kumquat is a popular Tet ornamental: a small tree heavy with golden fruit symbolising luck, prosperity and family reunion. The fruit is usually eaten fresh with the rind, or preserved in sugar or honey as a refreshing drink, made into candied kumquat jam, or brewed into kumquat-honey tea for coughs; abroad there is kumquat liqueur and marmalade. The rind is rich in essential oil (mainly limonene) used as a flavouring and in skin-care extracts. In folk medicine the fruit is expectorant, eases cough and stimulates digestion, and being rich in vitamin C it supports immunity. Kumquat is easily grown in pots and loves sun; in Vietnam plants are grafted, layered and trained into shape before Tet.