Saponaria caespitosa

Rock Soapwort. This is a lovely and tough rock garden or crevice plant from the Pyrenees where it grows in exposed sheer rock faces. Dense cushions of close-packed rosettes with narrow short green leaves. Pink-purple flowers are held on short 2" stems in groups of one to three. One becomes a group when hanging with the Threes. Full sun, good drainage, zones 3-8.