Densely hummock-forming, 20-30cm in diameter. Leaves imbricate, l-4mm long, ovate, recurved, ciliate at the base. Flowers solitary, just above the foliage, four or five-petalled, 6-10mm wide, white, late summer. Pyrenees and mountains of south-eastern and eastern Spain in dryish stony places. A.t. var. granatensis generally is more densely habited and bears five-petalled flowers (Spanish mountains only).