Acacia perpusilla, commonly known as the King Edward River wattle,[1] is a shrub of the genus Acacia and the subgenus Plurinerves that is endemic to a small area of north western Australia.
The shrub typically grows to a height of around } and has an erect and spindly habit with glabrous and resin-ribbed branchlets that have persistent stipules with a length of . Like most species of Acacia it has phyllodes rather than true leaves. The evergreen phyllodes are ascending to erect with a widely obovate shape and are dimidiate with a rounded upper margin and a straight lower margin. The phyllodes are in length and wide with many indistinct longitudinal nerves.[2]
It is native to a small area in the Kimberley region of Western Australia. It has a limited distribution and is found on Theda Station about south west from Kalumburu in the northern Kimberley along the King Edward River where it is commonly situated among sandstone outcrops along watercourses growing in skeletal sandy soils in shrubland communities where it is associated with Heteropogon contortus and species of Sorghum.[2]