Acacia nigricans is a species of wattle which is endemic to an area on the south coast of Western Australia.
The shrub typically grows to a height of and has hairy and ribbed branchlets with persistent and patent stipules. The leaves are composed of two pairs of pinnae with the proximal pinnae having a length of and the distal pinnae having a length of, these in turn are made up of two pairs of proximal pinnules and three to eight pairs of distal pinnules all of which have an oblong to narrowly oblong with a length of and a width of .[1] It produces yellow, globular flowers between mid-winter and late spring.
The species was formally described in 1807 by French naturalist Jacques Labillardière who gave it the name Mimosa nigricans, based on plant material collected from Esperance.[2] It was transferred to the genus Acacia in 1813 by botanist Robert Brown.[3]
It is often situated on coastal sand dunes, on granite hills and among rocks growing in grey or white sandy soils along the south coast of Western Australia in the Goldfields-Esperance regions. The bulk of the population extends from around Barker Inlet, about west of Esperance in the west out to around Israelite Bay in the east and extending inland to near Howick Hill, and is also found on several islands in the Recherche Archipelago usually as a part of heath and scrub communities.[1]