Acacia decora

Showy wattle, western silver wattle

Family: Fabaceae subfamily Mimosoideae

Acacia decora is a small to large shrub, often under 2 metres in height but sometimes to 5 metres tall.

This species is widespread west of the Dividing Range in Queensland, New South Wales and Victoria from Cooktown in the north to the Warby Range in Victoria. It is found on sandy and stony soils usually in eucalypt woodlands. It is also a wattle that regenerates along rural roadsides.

The phyllodes are lanceolate, to about 50 mm long and only about 7 mm wide; blue-green in colour.

Australian Wattles at least, can be broadly placed into 1 of 3 recognisable groups:

Group 1: Those that produce juvenile compound-bipinnate leaves and then change to producing adult-phyllodes which are modified-flattened petioles which form the foliage. This is combined with flowers produced in globular balls or heads (or ovoid heads). The heads can be singular in leaf/phyllode axils or arranged in groups.
Group 2: As for Group 1 but flowers are produced in longer rod-like spikes.
Group 3: Those that never produce phyllodes and retain the juvenile compound-bipinnate foliage into adulthood. These always produce flowers in globular balls (which are secondarily arranged into panicle or raceme-like groups in many cases).

This wattle belongs to Group 1.

Globular flower-heads are produced which can have about 30 tiny flowers in each head. These heads are about 4.5 to 6 mm across. The heads are then clustered in terminal (end of braches) and axillary (leaf axes) groups (racemes). It flowers from April to October.

Seed pods are straight to shallowly curved about 5–10 cm long.

In the garden

This is a hardy, showy species which is tolerant of a wide range of conditions. It prefers well-drained soils in light shade to full sun.

A. decora is a worthwhile addition to gardens in many areas of Australia as it is one of the showiest wattles.

Acacias can suffer from a number of pests, including borers, scale, galls and leaf miners. Growing plants suitable to your local environment minimises these pests occurring.

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

Most wattles will die in a fire and regenerate from seed. Some species exhibit suckering from basal parts and roots.

Acacia is a highly diverse genus, with over 1500 recognised species (placing it in the top-10 most-diverse plant genera) occurring in most continents except for Europe. Australia has about 970 spp., most of which are endemic. There are also about 10 exotic species. NSW has about 235 recognised species. Some species have become weeds in other states outside of their natural range (eg: wattles from Western Australia into NSW and vice versa).

Acacia – from Greek Akakia – which refers to an Ancient Greek preparation made from one of the many species; the name of which derives from akis, meaning “thorn” – referring to the thorns of species in Africa.

decora – from Latin decorus meaning “graceful in appearance”.

This species is not considered to be at risk of extinction the wild.

NSW Flora Online (PlantNET) – Acacia decora profile page http://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Acacia~decora

Greening Australia – Acacia decora factsheet https://www.greeningaustralia.org.au/wp-content/uploads/2017/11/FACT-SHEET_Acacia-decora.pdf

Wrigley, J.W. & Fagg, M.I. (2001). Australian Native Plants – Propagation, cultivation and use in landscaping. 4^th edition. New Holland Publishers, Pty. Ltd. Australia.

July 27, 2020