Noogoora burr is a short-lived, usually annual, shrub that is often abundant after spring and summer floods. It typically grows to around 1 m but may grow to around 2.5 m under ideal conditions and in the absence of a commonly-occurring leaf and stem rust and stem-boring and stem-galling insects.
The stems of the plant are rough to the touch, and feature short bristly hairs along its length. The leaves are usually a darker green towards the tips, and get paler as they get closer to the stalk. The leaves are covered in small bristles and are coarsely toothed around the edges, with three prominent reddish veins extending to each of the three lobes.
The burrs themselves grow typically to around 7–25 mm long and are covered in hooked spines.
Each burr contains two seeds. Seedlings are poisonous to stock and may cause losses if eaten in sufficient quantities, and the burrs are a costly contaminant in wool. Noogoora burr is a significant competitor in pastures and can be a serious weed in summer crops.