Acacia octonervia is a shrub of the genus Acacia and the subgenus Plurinerves that is endemic to a small area along the south western coast of Australia.
The spreading shrub typically grows to a height of 0.1to It has glabrous red-brown branchlets that can seem quite shiny and are covered in narrowly triangular and persistent stipules that have a length of . Like most species of Acacia it has phyllodes rather than true leaves. The rigid, cylindrical, green and erect phyllodes are straight to slightly curved with a length of and a diameter of and have eight distant raised nerves.[1] It blooms from August to November and produces cream-yellow flowers.
It is closely related to Acacia sulcata and belongs to the A. sulcata group of Acacias.[1]
It is native to an area in the Great Southern and Goldfields-Esperance regions of Western Australia where it is commonly situated on undulating plains and on lateritic rises growing in gravelly sandy, sandy-clay or loamy soils. The range of the plant extends from the Fitzgerald River in the west to around the Young River in the east with outlying populations found near Boxwood Hill further to the west. It is usually found as a part of dense low heath, open mallee and open dwarf scrubland communities.[1]