Acacia quadrilateralis

Northern Dagger Wattle

Family: Fabaceae subfamily Mimosoideae

A medium shrub, growing up to 3 metres tall with a spindly habit.

It has a mostly coastal distribution, found in eastern Queensland (up to Bundaberg – Gladstone and north of Yeppoon), and north-eastern New South Wales, down to Sydney (north of Botany Bay), with a southern disjunct population at Ulladulla. It typically grows on sandy soils over sandstone as a part of open Eucalyptus forest and woodland communities, as well as heathlands.

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 1.

The phyllodes (resembling leaves) are slender, rigid and evergreen and are 6 cm long and 0.1 cm wide. They are square-shaped in cross-section.

Very small staminate flowers occur between July and September and are produced as singular globular heads in the leaf axils, containing 12 to 30 cream to pale yellow-coloured flowers.

The seed pods are dark brown and resemble a string of beads. The pods are up to 9 cm long and 0.4 cm wide.

In the garden

Not a lot of information is available regarding its cultivation. It may be more common in cultivation in the future.

In the garden it prefers sandy soils but is adaptable to various soils. It grows best in full sun.

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 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 (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.

quadrilateralis – refers to the approximate tetragon (four-sided) shape of the cross section of the phyllodes.

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

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

Central Queensland Plants – Acacia quadrilataralis profile page http://www.northqueenslandplants.com/Australian%20Plant%20Families%20A-F/Fabaceae/Acacia/Acacia%20quadrilateralis.html 

Wikipedia – Acacia quadrilateralis profile page

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