Some of the most interesting euphorbias come from Madagascar.
Stenocactus is a genus of northern and central Mexican cacti of around 10 species related to Ferocactus.
Sometimes called "Living Stones".
Mammillaria is one of the larger genera in the Cactus family, and one of the most variable.
There were about 100 succulent Senecio species, some of which have been moved to the genera Caputia, Curio, and Kleinia. There are many non-succulent Senecio species.