Acacia macdonnelliensis, commonly known as the MacDonnell mulga or the Hill mulga, is a species of Acacia native to central Australia.[1] The Indigenous Australians the Alyawarr peoples know the plant as irrar, the Kaytetye know it as arleth-arlethe or arwele arleth-arlethe and the Western Arrernte peoples know it as irrkwarteke.[2]
There are two subspecies:
This bushy shrub or tree typically grows 3to tall and has deeply fissured grey bark. It has sparsely hoary to glabrous branchlets with obscure, resinous ridges. It has erect, glabrous to hoary, grey-green phyllodes with a narrow elliptic to linear shape that are 4to in length and 0.8to wide.[1] It produces yellow flowers in July. The dense golden flower spikes are 0.6to in length and have a width of 3to. After flowering linear pale brown seed pods form that are constricted between each seed. Each pod has a length of 3to and is wide. The dark brown seeds within are arranged longitudinally and are long.[1]
Acacia macdonelliensis is found in southern parts of the Northern Territory around Alice Springs and in far eastern Pilbara and north eastern Goldfields regions of Western Australia. It grows in areas of sandstone and quartzite along rocky ridges and creeklines. A. macdonnelliensis is drought and frost tolerant.