Densely hummock-forming, 20-40cm across. Leaves 1.5-3cm long, awl-shaped, semi-triangular in section, very stiff and spine-tipped. Flowers with 6-13mm long prickle-tipped sepals and shorter white petals, solitary or sometimes in twos and threes, summer. Southern Spain and Morocco, in dry screes up to 3000m. The name A. pungens is also a synonym of A. nuttallii, q.v.