Introduced, cool-season, annual, low-growing, sparsely-hairy herb. Leaves are deeply divided. Flowerheads are axillary, forming dense clusters in the centre of the plant; they are ± globose and 5–12 mm diam. Fruits are spiny, but lack wings. Flowering is in spring and early summer. A native of South America, it is a weed of short or sparse lawns and roadsides in full sun. An indicator of poor ground cover. The spiny fruit can be a nuisance. Control is best achieved by maintaining a healthy vigorous pasture. If herbicides are used, application should be between in late autumn and winter, before fruiting has commenced.