Sometimes called "Living Stones".
There are about 100 succulent Senecios.
Many from Madagascar, some from Africa and Asia in or near India.
Stapeliads are mainly from Southern Africa. They are called carrion flowers because of the smell they emit to attract flies for pollination.
Sansevieria is a genus of about 70 species of flowering plants, native to Africa, Madagascar and southern Asia. Common names include mother-in-law's tongue, devil's tongue, and snake plant.
The name means "Thick Foot". Native to only Southern Africa and Madagascar.
Dudleya from North America, Cotyledon from South Africa to Arabia
Gasteria is a genus of succulent plants, native to South Africa (and the far south-west corner of Namibia).
The varied genus Crassula contains around 200 species and many cultivars.