Sempervivum

Sempervivum (Brit. /sɛmpəˈvaɪvəm/,[1] U.S. [̩sɛ̃mpeɹ’vivũm]) is a genus of about 40 species of flowering plants in the family Crassulaceae, commonly known as houseleeks. Other common names include liveforever (the source of the taxonomical designation Sempervivum, literally “always/forever alive”) and hen and chicks, a name shared with plants of other genera as well. They are succulent perennials forming mats composed of tufted leaves in rosettes. In favourable conditions they spread rapidly via offsets, and several species are valued in cultivation as groundcover for dry, sunny locations.[2]

Houseleeks exist from Morocco to Iran, through the mountains of Iberia, the Alps, Carpathians, Balkan mountains, Turkey, the Armenian mountains, in the northeastern part of the Sahara Desert, and the Caucasus. Their ability to store water in their thick leaves allows them to live on sunny rocks and stony places in the mountain, subalpine and alpine belts. Most are hardy to US zone 4, and will handle warm climates to about zone 9.

Morphologically, they are similar to the genera Jovibarba, Aeonium, Greenovia, Aichryson, and Monanthes, occurring mainly in Macaronesia (Azores, Canary Islands, Cape Verde, Madeira). Some botanists include some or all of these genera within a wider interpretation of Sempervivum, particularly Jovibarba.

The name Sempervivum has its origin in the Latin semper (“always”) and vivus (“living”), because this perennial plant keeps its leaves in winter and is very resistant to difficult conditions of growth.[3] The common name “houseleek” is believed to stem from the traditional practice of growing plants on the roofs of houses to ward off fire and lightning strikes. Some Welsh people still hold the old folk belief that having it grow on the roof of the house ensures the health and prosperity of those who live there.[4][5] The plant is not closely related to the true leek, which belongs to the Allium genus.