Acaena ovina

Acaena ovina, commonly known as Australian sheep's burr or hairy sheep's burr, is a low-growing perennial herb of the family Rosaceae, native to south-eastern Australia, including New South Wales, Victoria, Tasmania and South Australia, where it occurs in grassy woodland, open pasture, road verges and disturbed ground. The plant forms a low rosette to spreading tuft 5–30 cm tall, with a stout woody rootstock and ascending to decumbent, hairy stems. The leaves are alternate, imparipinnate, 3–12 cm long, with 7–17 leaflets that are obovate to oblong, 4–15 mm long, with coarsely toothed margins and silky-pubescent, often greyish surfaces. The inflorescence is a dense, globose to ovoid head of small greenish flowers borne on a long erect peduncle; each flower has four sepals, no petals, and two stamens with reddish anthers. In fruit, the head becomes a spiny burr, each fruit enclosed in a hardened hypanthium 4–6 mm long armed with four stiff, retrorsely barbed spines that readily attach to wool and clothing. Flowering occurs in spring and early summer.