Acaena echinata

Acaena echinata, commonly known as sheep's burr or spiny sheep's burr, is a slender perennial herb in the family Rosaceae native to southern and eastern Australia and New Zealand, where it inhabits open grasslands, grassy woodlands, and roadside verges on a range of soils. It forms a low, creeping to ascending plant 10-50 cm tall, with slender, slightly woody stems and pinnate leaves bearing seven to thirteen ovate to elliptic, coarsely toothed leaflets that are green above and somewhat paler beneath. From spring into summer it produces small, dense, globose terminal heads of inconspicuous greenish flowers, each subtended by stiff, hooked spines on the receptacle. As the fruits mature these spines elongate and become rigid, forming the familiar burrs that readily attach to wool, fur, and clothing and so disperse the achenes effectively across pastures.