Sempervivum

"Sempervivum have long fascinated gardeners and are useful plants for gardening situations in which other plants might fail. Many people are aware of only a single, rather uninteresting green cultivar, but selections from the wild and the work of hybridizers have resulted in over 7,000 cultivars with a range in size from 1/2 in. to over one foot in diameter and colors from gold to black. Clearly the gardener has never had a better choice. This book covers all aspects of their history, taxonomy, culture, propagation, hybridizing, people involved in the production of Sempervivum, and a long list of cultivars that are recommended for the gardener. Color illustrations show not only the cultivars, but garden uses and cultural practices."--Amazon.com.