Acacia decurrens

Green Wattle, Sydney Green Wattle, Boo’kerrikin (Dharawal)

Family: Fabaceae subfamily Mimosoideae

Acacia decurrens is a tall shrub to tree, reaching 12 metres tall.

The bark is green with green branches which have winged ridges.

Grows in dry sclerophyll forest or woodlands, with much of its existence in the central coast subdivision of NSW, extending to the central tablelands, southern tablelands and western slopes. It is considered to have naturalised outside of its main range, in SA, WA, Qld, Vic and Tasmania.

It usually grows on heavier soils, often near creeklines. It can be a dominant midstorey plant in some woodland and forest vegetation, often with a mixture of age classes with dead trees and regenerating saplings.

The leaves are compound-bipinnate (jacaranda-type), mid-green, to about 12 cm long with pinnules (leaflets) to about 1.5 cm long and much more widely spaced compared to other bipinnate wattles (somewhat resembling a hair comb). The leaves typically have jugary glands but no interjugary glands.

Flowers are produced in globular heads, up to 7 mm diameter, with up to 35 very small staminate flowers per head. The heads are clustered into showy racemes and/or panicles, produced in the leaf axils and at the terminals, with many heads per raceme or panicle. Flowers are a rich bright yellow, with flowering usually starting in July-August. Trees are very showy when in flower.

Pods are straight to curved, to 11 cm long and about 1 cm wide. They are produced in large numbers and can cover the ground when shed.

In the garden

An attractive flowering wattle but may be too big for some gardens. Also tends to be short-lived, prone to borer attack. However, can be used to create a privacy or screen at a high level. Bee-attracting. Will also create some light shade.

May be used in situations where establishing other medium trees is difficult. Grows very quickly.

Very hardy. Will tolerate sun and shade. Tolerates frost and hot weather. Not too fussy about soil. Not often found on very sandy soils.

Propagation

Propagation is easy from scarified seed by covering with boiling water for 24 hours and discarding any seeds still floating on the surface.

Other information

Regenerates readily from bushfire through the soil seedbank.

Acacia – Greek translation of akis – meaning a thorn or “thorny”.
decurrens – from the Latin meaning decurrent – where an organ extends down past the point of insertion. In this case, the leaf petioles extend down the stem as a ridge, a useful identification feature for this plant

Not considered to be at risk in the wild.

https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Acacia~decurrens 

http://www.anbg.gov.au/acacia/species/A-decurrens.html

https://keyserver.lucidcentral.org/weeds/data/media/Html/acacia_decurrens.htm

By Dan Clarke