About 500 species of shrubs, perennials and annuals of almost worldwide distribution but mainly northern hemisphere and temperate Asia. They have compound pinnate, digitate to ternate leaves, which in the perennial species are carried in tufts, mats or hummocks. The five-petalled flowers superficially resemble small single roses but are characterised by an epicalyx (sepal-like bracts which alternate with the true sepals).
Several dwarf members of this genus are essential rock garden plants and many more are valued by the enthusiast. Most of them thrive in fertile, well drained but not dry soil in a sunny position. Where necessary, additional cultural comments are made in the species' descriptions. Propagation by seed when ripe or spring in a cold frame; perennials also by division in late winter or early spring; some of the more woody-based ones also by late spring or summer cuttings. The shrubs can be increased by cuttings in late summer in a cold propagating frame, or outside in autumn.