Low cushion to mat-forming about 4cm tall. Leaves glaucous-grey, almost spherical, 2-3mm long, usually alternate but sometimes opposite, tightly packed. Flowers five-petalled, 6mm across, white with pink keels, in small cymes. North Africa and southern Europe, on rocks and walls. Easily controlled and a very worthwhile plant if grown outdoors but can become a nuisance if allowed into the greenhouse as every detached leaf becomes a new, unwanted plant. S.d. 'Abbey Dore' is an opaline green-leave mutant. S.d. 'Atlas Mountain Form' (syn. S.d. subsp. oblongifolium) is often grown under glass as a specimen plant where it loses its overall attractive pink colour from the larger, 2cm long leaves and becomes less compact. Needs protection in winter in colder areas. S.d. var. glanduliferum (syn. S. corsicum) is a large hairy form with purple anthers. S.d. var. macrophyllum is often erroneously sold as S. quinquefarium (see S. brevifolium). It is a large form with glaucous greeny-white turgid leaves in five spiral rows. S.d. var. mesatlanticum appears to be the form which grows into dense, hemispherical hummocks tightly packed with small, pinkish-grey slightly elongated leaves. It has yellow anthers. It is sometimes sold under the name 'Mucronatis'. A superb specimen plant which can be ruined by heavy rain. S.d. 'Lloyd Praeger' is a small, densely hairy form which also disintegrates during heavy rains leaving bare stems with hundreds of detached leaves at the bases. Each leaf roots. This form has no red or pink pigmentation but is a clear bright blue-green. The anthers are purplish-black. is162 S.d. var. suendermannii from the Pyrenees is another large, hairy form.