About

Acacia decurrens, commonly known as black wattle, Sydney green wattle or early green wattle and other common names, is a species of flowering plant in the family Fabaceae and is endemic to New South Wales, Australia. It is a tall shrub to tree with bipinnate, dark green leaves, spherical heads of golden yellow flowers and thinly leathery pods.

Cultivated throughout Australia, Acacia decurrens has naturalised in other Australian states and introduced to many other countries.

How to grow it

Acacia decurrens adapts easily to cultivation and grows very quickly. It can be used as a shelter or specimen tree in large gardens and parks. The tree can look imposing when in flower. Cultivation of A. decurrens can be started by soaking the seeds in warm water and sowing them outdoors. The seeds keep their ability to germinate for many years.

Fieldwork conducted in the Southern Highlands found that the presence of bipinnate wattles (either as understory or tree) was related to reduced numbers of noisy miners, an aggressive species of bird that drives off small birds from gardens and bushland, and hence recommended the use of these plants in establishing green corridors and revegetation projects.

Where it grows

Acacia decurrens is native to the coast and tablelands of New South Wales and the Australian Capital Territory mainly south from the Hunter Valley, and is common in the Sydney region. It grows in forest, woodland and heath, often on river banks. It is found in altitudes up to 1,000 m (3,300 ft) with rainfall between 700–1,400 mm (28–55 in) per year, and grows with trees such as grey gum (Eucalyptus punctata) and narrow-leaved ironbark (E. crebra) in loamy soils derived mainly from Wianamatta shale and sandstone.

Uses

Uses of Acacia decurrens include chemical products, environmental management, and wood. The flowers are edible and are used in fritters. An edible gum oozing from the tree's trunk can be used as a lesser-quality substitute for gum arabic, for example in the production of fruit jelly. The bark contains about 37–40% tannin. The flowers are used to produce yellow dye, and the seed pods are used to produce green dye. An organic chemical compound called kaempferol gives the flowers of A. decurrens their color. It has been grown for firewood, or as a fast-growing windbreak or shelter tree.

Other Acacia plants

Acacia abbatiana · Acacia abbreviata · Acacia abrupta · Acacia acanthaster · Harrow Wattle · Acacia acellerata · Gold-dust acacia · Acacia aciphylla · Acacia acoma · Acacia acradenia · Strap Leaved Wattle · Acacia acuaria