Acacia oxycedrus

Spike wattle

Family: Fabaceae subfamily Mimosoideae

A prickly but very attractive and interesting wattle, growing to 3 m high by 2 m wide.

In NSW, it is mainly confined to the Greater Sydney Basin, from Kulnuru to Gerringong and west to the Lower Blue Mountains. Then with disjunct populations on the far south coast, south of Eden. It is much more common in Victoria, growing through much of the southern half of the state, extending into South Australia, mainly in the Mt Gambier-region, north to Mundulla.

It is typically found on sandy soils and subtrates (sandstone), in dry sclerophyll woodland, forest or heath.

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 species belongs to Group 2.

The phyllodes (modified leaves) are dark green, rigid and sharp-pointed, to 4 cm long and about 0.5 cm wide, usually with 3 or 4 longitudinal prominent veins.

Flower heads are cylindrical (spikes) consisting of very small staminate flowers, to 3 cm long and very showy with up to 3 spikes produced in each phyllode axil; bright yellow or pale yellow, appearing from July to October.

Pods to 10 cm long but less than 1 cm wide.

In the garden

An attractive frost hardy and adaptable plant that grows best in a sunny, reasonably well drained positions in most soils. An excellent plant for small bird-nesting, due to its prickly protective foliage.

Grows in places like Sydney sandstone woodland, so very hardy in terms of sun and temperature tolerance.

It can be very showy with prolific flowers.

It is one of those wattles which should be grown much more but may be difficult or temperamental in gardens. It is reported to grow mostly well (see resources below). Seeds are aviable comercially. Check with native plant nurseries for availability.

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


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

Likely regenerates from seed after fire.

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 (e.g., 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.

oxycedrus from the Gk. oksis (oξσύς) meaning “acute” (sharp)  and cedrus – a genus of cedars – referring to the species likeness to a prickly or sharp cedar-pine.

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

Australian National Herbarium – Acacia oxycedrus profile page          http://www.anbg.gov.au/acacia/species/A-oxycedrus.html

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

Wikipedia – Acacia oxycedrus profile page                                https://en.wikipedia.org/wiki/Acacia_oxycedrus

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

By Jeff Howes. Editing and additional text by Dan Clarke.