Wikipedia
Jovibarba ("beard of Jupiter") is a small genus of three species of succulent flowering plants in the family Crassulaceae, endemic to mountainous regions in the southeastern quadrant of Europe. The genus is sometimes classified as a subgenus of Sempervivum, to which it is closely related. Jovibarba have pale-greenish-yellow or yellow actinomorphic flowers with about six petals, while Sempervivum have generally pinkish flowers with around twice as many petals, which open more widely than jovibarba flowers. The common name hen and chicks is applied to some Jovibarba species (and also species in several other Crassulaceae genera).
Most jovibarbas, like sempervivums, reproduce via offsets in addition to producing seeds via sexual reproduction. Jovibarba heuffelii does not produce offsets on stolons. Instead the offspring of this plant are produced within the mother plant. To propagate it must be split with a knife. The other two jovibarba species are commonly called rollers. They produce offsets that are lightly attached and easily pop off and roll away from the mother plant. Offsets survive the main rosette, which is monocarpic.