Acacia incognita, also known as false sugar brother,[1] is a shrub or tree belonging to the genus Acacia and the subgenus Juliflorae that is endemic to Western Australia.
The shrub or tree typically grows to a height of and has an obconic form. It has slightly crooked stems that are not fluted with fissured on present on the main stems and the upper branches. It has resinous new shoots with scattered reddish glandular hairlets. The glabrous branchlets can have some hairs between the non-resinous ribs. Like most species of Acacia it has phyllodes rather than true leaves. The green to grey-green and slender phyllodes are coarsely pungent and have a straight to shallowly incurved shape with a length of and a width of with fine longitudinal nerves.[1] It blooms inconsistently between January and October producing simple inflorescences that occur singly or, less frequently, in pairs in the axils and have spherical to short-obloid shaped flower-heads that have a length of and a diameter of . The thinly coriaceous to crustaceous seed pods are straight to shallowly curved with a length of and a width of with longitudinal nerves. The shiny brown seeds found in the pods have a narrowly elliptic or oblong shape have a length of with a creamy white aril.[1]
It is native to an area in the Mid West region of Western Australia from around Mullewa in the west through to around Yalgoo in the east and to around Karara Station to the north of Morawa in the south. It is often situated on plains or low rises growing in loam or loamy clay soils as a part of Eucalyptus woodland communities or Melaleuca shrubland communities.[1]