Semper-Vivum (live-forever) Completely hardy, outdoors all year, does not like being grown indoors. Will protect your house from lightning.
Sempervivum: These succulent plants are commonly known as Houseleeks. They are an alpine plant, hardy in Britain, and will stay outside all the year. They grow better in the garden than in the house, and can exist in very little, or very poor soil. But they need FULL sunlight, and do not like to be in wet soil for too long, so should be planted in well drained soil. Repot in house plant compost (or John Innes), with extra grit and plenty of drainage material (and a hole) at bottom of pot, they do best in clay pots. They spread each year, forming new plants, and when they get to maximum size will send up a flower stalk (pink flowers usually). Each plant which flowers will then die but leave many offsets behind. They are also attractive when grown in crocus pots (plant one plant in each of the holes), or in holes in bricks.
The Emperor Charlemagne in France ordered every house roof in France to be planted with these plants, to protect the house from lightning.
They have also been used in wart-charming. There are many, named, varieties.
This one is Sempervivum Arachnoideum (Spider Web houseleek). The flower is terminal, usually pink.