About 300 species of small annuals, perennials and subshrubs from the northern temperate zone and temperate South America. They have small, narrow, simple leaves forming rosettes which are gathered into tufts, mats or cushions. Small, four-petalled, white or yellow or rarely orange to red or violet flowers, carried in short racemes in spring.
The cushion-forming members and some of the mat-formers rank with the choicest of alpines and are very much at home on the rock garden, raised bed, scree, dry wall or alpine house. Freely draining but otherwise ordinary neutral to limey soil and a sunny site are basic requirements. Woolly-leaved species, e.g. D. mollissima and probably most South Americans are best in the alpine house, or with a pane of glass overhead to keep off winter rain. Propagation by seed in spring or when ripe and by cuttings of single rosettes in late summer.
a, D. aizoides; b, D. bryoides; c, D. incana; d, D. polytricha;