A medium shrub, growing up to 3 metres tall with a spindly habit. It is found in south-eastern Queensland 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 woodland communities and heathlands.
The phyllodes (resembling leaves) are slender, rigid and evergreen and are 6 cm long and 1 mm wide. They are square-shaped in cross-section.
The 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 4 mm wide.
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.
It likely regenerates from seed after fire.
Acacia – from Greek acis, a thorn.
quadrilateralis – refers to the approximate tetragon (four-sided) shape of the cross section of the phyllodes.