The small-leaved tamarind, also known as the native tamarind, is the popular name for a number of species that are not actually related to the real tamarind. Around ten different species exist, part of the Diploglottis genus and the Sapindaceae family. These plants are native to New Guinea and eastern Australia, where they inhabit jungles and the edges of forests in areas with high humidity.
D. australis is one of the most popular varieties from Australia, where it is named the native tamarind. It is a common street tree in Lismore and other parts of the Northern Rivers area of the New South Wales state.
D. campbellii, which is also named the small-leaved tamarind, is another species endemic to the Australian continent. It is only found in a few locations, where no more than three trees are found, which makes it a very rare and endangered plant. Only 42 established trees are known today in the wild in the entire area of north-eastern New South Wales and south-east Queensland.
Small leaved tamarinds are useful as screening trees because they have a compact crown and can grow up to 30 meters high. The small leaved tamarind fruits are found in small capsules with three lobes and are edible. Due to the recent popularity of bush food, the small leaved tamarind tree is today cultivated. Fruits become red when ripe and are a popular raw material for jam.
The species is endangered in its original rainforest habitat but it is increasingly used to provide shade in parks and gardens. Small leaved tamarind also provides attractive red fruits that hang in capsules. They are usually transformed into preserves or jams and are rarely consumed fresh due to the very sour taste.
The small leaved tamarind leaves consist of 4 to 8 leaflets and have an overall length between 10 and 35 cm. Individual leaflets have a length of 5 to 10 cm and a width between 2 and 4 cm, with a glossy upper surface and a pale underside, sometimes covered in hair. They have an ovate or elliptic-oblong shape, with an asymmetric base and an acute or shortly acuminate apex. Leaflet stalks are between 2 and 5 mm long, while leaf stalks can reach between 3 and 6 cm in length.
The creamy or brown flowers are grouped in panicles. Small leaved tamarind fruits consist usually of two lobes but sometimes have only one or three. They are capsules with a round shape and smooth surface, inside there is one seed with an aril that has a deep red or yellow color.
The D. campbellii species has lost most of its natural habitat due to land clearing. Some isolated small leaved tamarind trees still survive on cleared fields but most of them are found along roads or in the few remaining patches of rainforest.
These medium-sized evergreen trees with a dense crown are known for the delicious pulp of their large orange fruits. The bloom happens between the months of November and January, when small cream or brown flowers appear. The capsules develop in February or April and eventually open when the red fruits inside become ripe. They are rarely consumed raw but are excellent ingredients in cooking and pair well with cold meat and cheese. They can also be prepared as jellies, sauces, jams, spreads, coulis and fruit chutneys.
The bloom is between the months of November and January. The initial small flowers transform during the spring into large bulbous pods with a yellow or brown color. Once ripe, the pods open up and the small red fruits inside become visible. The rich tart taste of the flesh is suitable for sweet and savoury recipes. It is a popular gourmet cooking ingredient and can also be processed in various ways.
The small leaved tamarind tree has a very high yield and produces many kilograms of fruit every year. Plucking off the tree after the fruits are ripe is the easiest way to harvest them.
All varieties of this species enjoy soils with a high organic content and good drainage, as well as partially shaded locations. In cultivation it needs organic fertilizers in the spring and plenty of water during dry periods.
As an ornamental tree, the small leaved tamarind can be placed in a large pot, with regular pruning in order to manage its size. If planted in the garden, it can grow up to 30 m in height.
The small leaved tamarind is now cultivated in large numbers but the wild populations are threatened with extinction. The main reason is the loss of its natural habitat due to deforestation. Without radical action, it is likely that the tree will soon disappear completely from the wild and become a garden-only species. This rainforest tree with a dense and compact canopy is already very rarely found in forests.
The edible fruit has a very tart and spicy flavour, which makes it suited for preserves or sauces but rarely eaten out of hand. Small leaved tamarind used to be almost impossible to find, due to the very low number of wild trees that remain. The popularity of bush food has led to more and more commercial plantations, so the small leaved tamarind is now commercially available. This has also saved the species from extinction.
The small leaved tamarind tree is found today in large numbers in the Lismore area. It has proven to be surprisingly easy to cultivate, as both a source of bush food and as an ornamental tree.
The small leaved tamarind tree can grow up to 30 m in the wild and develop a nice spreading canopy, but only reaches 8 m in cultivation. It is an evergreen rainforest species that grows slowly. Small leaved tamarind likes fertile soils rich in mulch and organic matter, while the position must offer full sun or partial shade. It also tolerates poor soils based on quartz monzonite, as well as volcanic ones derived from basalt.
The natural habitat of the small leaved tamarind tree is limited only to the low areas of the NSW-Queensland border, in hot subtropical rainforests. Small leaved tamarind is found in several forest types, including lowland subtropical rainforest and drier subtropical rainforests. The seasonal climate and the latitude have a direct influence on the bloom season, which is variable. The small leaved tamarind fruits start to mature between January and April, with the months of February and March being usually the most productive.