Acacia Garden

The wattles (genus Acacia) belong to the family Mimosaceae, one of the three families (the other two being Caesalpiniaceae and Fabaceae) which form the very large cosmopolitan group of plants which have pea-pod-like fruits. The acacias originated in Africa and India in tropical climates. The ancestors of Australia's present day acacias probably entered tropical Australia from India before the break up of the southern hemisphere supercontinent of Gondwana. Becoming isolated in Australia they diversified and spread across Australia, eventually occupying the tropical as well as the temperate regions of the continent. They are now found in all vegetation communities except the sub-alpine heaths and the tropical rainforests.

The majority of the 1100 or so Australian species of Acacia are of the "phyllodinous" type, i.e. they have modified leaf stalks which function as, and look like, a leaf. The minority of the species which have true (bipinnate) leaves mostly occur in the temperate areas of Australia and are thought to be the most recently evolved of the Australian species. In the Americas and Africa, all species of Acacia have true bipinnate leaves and many are armed with large thorns.

In Australia, Acacia plants are an important component of the ecology and food web in most communities and particularly in arid communities, often referred to as Mulga. They also benefit the soil by adding nitrogen to it. A few species, such as Acacia melanoxylon (Blackwood), provide useful timber, while some others may provide cattle fodder in times of drought. They were important to the Aborigines who used many of the different acacias for both food and the making of implements.

About 85 species of Acacia are indigenous to the Hunter Region and they form a conspicuous component of the natural flora, and most are represented in this Gardens' collection, including five species which are regarded as rare or endangered. Included as also some representatives from across Australia.

The Acacia Loop is a short walk around the Acacia Garden and most of the acacias within the Loop occur in the Hunter region. There is also a small area devoted to the grass trees (Xanthorrhoea species).