pronounced: ZIZ-ih-fuss maw-rih-tee-AY-nah
pronounced: ZIZ-ih-fussJOO-joo-buh
Ziziphus is from the Greek ζιζυφον (zizyphon), their name for Zizyphus vulgaris, a medicinal plant, and derived from the Persian zizafun; mauritiana is from the Latin mautitanicus, Mauritania in North-west Africa. Jujuba is probably derived from an Arabian name for the plant. The Kew Plant list gives Ziziphus jujuba as the accepted name; but I have followed the normal Queensland usage.
The species is thought to have originated in the Indo-Malaysian region of Asia, and is now widely naturalized throughout the Old World tropics. It can form dense stands and become invasive, as it has done in northern Australia. In Queensland it is densest in areas formerly associated with mining, around Charters Towers, Mingela, Ravenswood and Hughenden, but also occurs in other parts, including the outskirts of Townsville, where it was first recorded in 1916. Although great efforts have been made to eradicate the plant on Magnetic Island, a plant or two remain in the Bolger Bay area, and also in Horseshoe Bay.
It is a medium sized tree that grows vigorously and has a rapidly-developing taproot, so it is well-adapted to drought conditions. The species varies widely in height, from a bushy shrub 1.5 to 2 m tall, to a tree 10 to 12 m tall with a trunk diameter of up to about 30 cm. The plant may be erect or wide-spreading, with gracefully drooping thorny branches and zigzag branchlets, with a leaf and thorn at each angle. It is densely branched, from ground level in many cases.
The leaves are alternate, ovate or oblong-elliptic with a rounded apex. There are 3 depressed longitudinal veins at the base of the leaf. The leaves are roughly 3 cm long or a little more, and their margins are finely toothed. They are dark green and glossy on the upper side, and pubescent and pale green to grey-green on the lower side. Depending on the climate, the plant may be evergreen or deciduous.
The flowers are tiny, yellow, 5-petalled and are usually in twos and threes in the leaf axils. They are white or greenish white in colour, and have an unpleasant odour.
The fruits are soft juicy drupes, orange to brown, 2 – 3 cm long, with edible white pulp surrounding a 2-locular pyrene. Under cultivation they can reach up to 6.25 cm long and 4.5 cm wide. They may be oval, obovate, spherical or oblong, and the skin smooth or rough, glossy, thin but tough. The fruits ripen at different times, even on the same tree. The ripe fruit is sweet and sour in taste; both the flesh texture and taste are reminiscent of apples. They probably taste better when they are slightly under-ripe, as the fully ripe fruits become rather mushy. There is a single hard oval or oblate rough central stone containing 2 elliptic brown seeds 5 – 6 mm long.
The flowers are protandrous, so fruit set depends on cross-pollination by insects attracted by the fragrance and the nectar. The pollen is thick and heavy, so is not air-borne. Honeybees are the main pollinators. The honey from these flowers is sweet, and quite prized by beekeepers. The seeds are spread by birds, native animals, stock, feral pigs and humans. The plant also regrows from damaged roots.
Locally, the fruit is eaten raw by children, or at least it was when I was a child, and when what are now the inner suburbs of Townsville were wasteland covered in Chinee apple bushes, and where we ranged about on our bicycles . In countries such as India where the plant is cultivated, the fruit is mostly eaten raw, but sometimes stewed, pickled or used in beverages. Slightly underripe fruits are candied by a process of pricking and immersing in a salt solution. Ripe fruits are preserved by sun-drying, and a powder is prepared for those times of the year when the trees are not in fruit. in Ethiopia, the fruits are used to stun fish!
Timber from the tree is reddish in colour, hard, strong, fine-grained, fine-textured, tough and durable. It has been used to line wells, to make legs for bedsteads, boat ribs, agricultural implements, and tool handles. It turns well. The wood makes good charcoal, and is also used as firewood. In tropical Africa, the flexible branches are wrapped around the conical thatched roofs of huts as retaining bands, and are twined together to make impenetrable walls for livestock enclosures.
There are many medical uses. The fruits are applied to cuts and ulcers; they are used to treat pulmonary ailments and fevers, and, mixed with salt and chilli, to treat indigestion and biliousness. The dried ripe fruit is used as a laxative. The seeds are used as a sedative, and are also taken, usually mixed with buttermilk, by pregnant women for morning-sickness and abdominal pains. A paste made from the bitter astringent bark is applied to sores, and a decoction made from the bark is taken to treat diarrhoea and dysentery. A decoction made from the roots is used as a purgative, and the powdered root is dusted on to wounds. 
The juice from the root bark is taken to alleviate gout and rheumatism, but, unless used in moderation, may be toxic. A infusion made from the flowers is used as an eye lotion.
The species is a Class 2 declared plant under Queensland legislation.
