The kangaroo apple (Solanum aviculare) belongs to the same family as many economically significant food plants such as potato, tomato and egg plant (aubergine). It is one of 87 species endemic to Australia, growing wild in eastern areas of Queensland, NSW and Victoria as well as on Lord Howe Island, New Zealand and New Guinea. Two distinct species of kangaroo apple are now recognised, both of which share the same common name and properties and have a similar appearance and general range, although Solanum aviculare prefers damper environments than S. laciniatum.
This upright, fast-growing, evergreen shrub reaches a height of 1 to 4 metres. It has a soft-wooded trunk that persists for several years. The 30cm long leaves are deep green above and lighter on the under-surface and are either lanceolate in shape or lobed. The hermaphroditic flowers, which appear in spring and summer, range in colour from white, through mauve to bluish-violet. They have a deeper coloured star-shaped marking at the base and bright yellow anthers. Native bees aid fertilisation by buzz pollination – the bee sits on an anther and vibrates its wings causing the pollen to be released and stick on its body. The pollen is then transported to the next flower the bee visits and cross pollination results. Egg-shaped berries, about 2 cm long, following the flowers, are initially green but mature to an orange-red colour. All of the green parts of the plant and unripe fruit are poisonous. When ripe, the berries soften and may split exposing hundreds of tiny seeds. The pulp is juicy and sweet. Eaten by birds, the seeds are spread and germinate in new areas. The common name is derived from the kangaroo foot-print-like shape of the deeply lobed leaves and the fruit.
For thousands of years indigenous Australians and Maoris have used the kangaroo apple as a food source and in their medicine. The ripe fruit is high in vitamin C and beta-carotene and contain phenols (which are beneficial antioxidants that protect against heart disease, stroke and cancer), important alkaloids and a steroid that assists in the production of cortisone. It also contains tryptophan that is important in healthy skin and hair. In addition to being a significant nutritional source, kangaroo apple (known as mookitch by the Gunditjmara) fruit was applied as a poultice on swollen joints and was an effective anti-inflammatory.
Ripe kangaroo apple fruit can be eaten raw or cooked, can be added to baked goods or made into jam, jelly or chutney. Since the 1960’s this plant has been extensively cultivated in Russia, India and China for use in the production of medicines (e.g. the contraceptive pill) and beauty products. An extract of the fruit is used in commercially produced skin conditioners whilst an oil extracted from the seeds acts as an antioxidant, humectant, skin conditioner and protector in cosmetics.
In the garden the kangaroo apple is useful as a hedge, in the understorey of wind-breaks, for bank and erosion stabilisation and in sheltering more delicate plants until they are established. They are used as a rootstock for grafting the tree tomato (Cyphomndra betacea) and eggplant. This species has been used in the reclamation of mine wastes as they are able to grow in soils with a high concentration of heavy metals. As early colonisers of cleared or disturbed areas, they are a significant regeneration species.