S. tectorum
S. juvanii
J. hirta
J. arenaria

Flowers of the genus Sempervivum have more than 7, usually  12 or more petals and sepals which are spread.

Blooming common houseleek

 S. tectorum.

Flowers of the genus Jovibarba have campanulate flowers with mostly 6 petals and sepals.

 Flower of J. hirta

Jovibarba globifera subsp. hirta.