Height to approximately 1 m. An annual herb with erect branching stems. Both stems and flower stems (inflorescence) may be smooth to slightly hairy. The toothed, opposite leaves are 8-20 cm long and range from un-lobed to deeply three-lobed. The short leaf stalks are sometimes slightly winged. The 6-9 yellow ray-petals of the flowers are clustered at the ends of branches. Two rows of short, green, leaf-like involucre bracts (modified leaf) surround each head. Numerous tiny single-seeded fruits (achenes) develop on each head after flowering. Achenes are tan or brown coloured, 5-7 mm long and wedge-shaped, each with 2-4 barbed needle–like appendages (awns) that assist in seed dispersal by hooking onto fur, feathers or clothing.