Main stems 15-60cm long, procumbent to semi-erect. Leaves 2-8cm long, composed of nine to twenty-seven oblong to broadly elliptic leaflets which are hairy, especially beneath, and pinnately cleft into several narrow segments. Flower heads cylindrical to shortly so, 1-1.5cm long on stems 6-30cm high. Sometimes there are small lateral flower clusters beneath the main one; stigmas purplish, stamens dark purple to blackish. Fruiting heads larger, each individual fruitlet hard, almost woody, pubescent and spiny all over. Southernmost Chile and Argentina in open plant communities in sand and shingle, also in Nothofagus antarctica woodland and open grassland. A. poeppigiana, A. platyacantha, A. integerrima and A. trifida are all similar and could be regarded as part of one very variable species. It is a widespread nuisance throughout Argentina and Chile, but mainly in the south, and is really rather too coarse and undistinguished a mat-former for the rock garden.