Bristly Starbur is an annual herb characterized by hairy stem, yellow-green florets, opposite leaves and fruits with hooked spines. Stems are erect, 20-80 cm long, diffusely branched, velvety with long hairs. Leaves are elliptic to ovate, 2-10 cm long, 1-7 cm wide, with glands on lower surface. Leaf margins are toothed to nearly entire, gradually tapering to the base, stalkless. Flower-heads are yellow, 4-5 mm in diameter. Burs are wedge-shaped, strongly compressed, 4-7 mm long, the ribs bearing 1-2 rows of hooked prickles 1-2 mm long, the 2 apical prickles stout, curved or straight, 3-4 mm long.