About 40 species of hardy, succulent perennials from Europe, western Asia and North Africa. They form mats or low hummocks of dense rosettes composed of fleshy, oblong to obovate leaves which can be basically green or grey variously flushed or tipped with red or purple. Each rosette is monocarpic, living one to several years before flowering, but producing offsets annually. When mature the rosettes elongate to an erect, leafy stem bearing one or more cymes of starry flowers composed of nine to twenty narrow petals. (See also Jovibarba, a split from Sempervivum having flowers with fewer petals fused into a tube).
Indispensable plants for the rock garden, raised bed, scree, dry wall, sink and alpine house. Although attractive in bloom, they are grown mainly for their architectural foliage. Splendid plants for the beginner. Any sharply drained soil is suitable, and a sunny site, though some shade is tolerated. Propagation by detaching offsets when well grown, generally in early autumn or the following early spring, or by seed in spring.
a, S. arachnoideum; b, S. dolomiticum; c, S. montanum; d, S. tectorum;