pronounced: SIT-russ reh-tick-yoo-LAR-tuh
Citrus is the ancient Latin name for the citrus tree; reticulata is from the Latin reticulatus, net-like. ‘Imperial’ is a chance hybrid selected about 1890 at Emu Plains, some 50 km west of Sydney. It is thought to be a hybrid of either ‘Mediterranean’ or ‘Willowleaf’ with another mandarin that was probably ‘Emperor’. This is one of Australia’s most important Mandarin types, being widely planted throughout the existing mandarin-growing regions, particularly in Queensland. Because of its early maturity, attractive appearance and pleasant flavour, it commands a premium in the markets. It is also widely grown as a back-yard tree. It prefers a moderately heavy loam, with added compost and sand, and likes a sunny position. It is intolerant of waterlogging.
The tree is grafted on to a variety of rootstocks. It is quite vigorous, medium in size (up to about 4.5 m high by 3 m broad), upright, virtually thornless. The petioles are narrowly winged. The leaves are long, slender (up to about 10 cm by 4 cm), and taper to a point. The lateral veins are not very obvious, and form loops inside the blade margin. The leaves are very aromatic when crushed. The tree has some tendency to alternate bearing.
The pleasantly-perfumed flowers are bisexual, and are self-fertile. The petals are glabrous, about 12 by 5 mm, with greenish oil-dots, large and conspicuous, visible to the naked eye. There are about 15 stamens, the filaments fused to form a tube about 6 mm long, with free filaments about 1 mm long.
The fruits are medium in size, oblate to broadly obovate, with the apex depressed. The rind is very thin, leathery, smooth and glossy, yellowish to pale orange at maturity. There are 9 – 11 segments, with comparatively few seeds, easily separable. The easiness of peeling makes this a very popular fruit with children.
The mandarin tree is a food plant for several moth and butterfly larvae, including:
• the Ailanthus Leaf Roller Psorosticha zizyphi;
• the Dainty Swallowtail Papilio anactus; and
• the Fuscus Swallowtail Papilio fuscus.
The essential oil produced from the peel by cold compression is used as a flavouring agent in foods and drinks, in the perfume industry, and in traditional medicine. Medicinally it is used as an antiseptic, and as an antispasmodic to treat cramps and breathing problems. It is also used in the treatment of circulatory problems, to hasten the healing of wounds, to improve digestion, and as a sedative. It is much used in Chinese Traditional Medicine.