Sempervivum are succulent, rosette forming plants belonging to the Crassulaceae family. They are commonly known as Hens & Chicks, Houseleeks or Hen and Chickens. The main attraction of these plants is their colourful rosettes of leaves. These range from bright yellow, through various shades of green, grey, pink, purple, red, orange and brown, to almost black in some varieties. The leaves may be dull or glossy, or covered with soft down or longer hairs. Small silvery hairs are commonly found along the leaf margins and in many varieties the leaf tips bear a tuft of longer hairs that can form a "spiderweb" over the surface of the rosettes. Leaf shape can also vary from short, succulent, almost round leaves to long, tapering, finely pointed ones.

The rosettes are most striking in the spring and summer but even in the winter when growth stops, many varieties remain attractively coloured. It is the endless range of different leaf shapes, colours and textures that make this group so interesting to enthusiasts.