Acaena echinata
Acaena echinata, commonly known as sheep's burr, is a species of perennial herb, in the Rosaceae family, native to Australia. It grows to a height of 25–40 cm and has shiny, green fern-like leaves 60–150 mm long which are hairy on the underside. Its tiny pale green flowers form a spike and have purple stamens. The burrs it produces are sharply barbed.