Both genera are from South Africa and are closely related.
Melocactus are recognizable by the large cephalium that develops on mature plants. They are native from Brazil to Southern Mexico, including the Caribbean.
Parodia is a genus of cactus native to the uplands of Argentina, Peru, Bolivia, Brazil, Colombia and Uruguay. There are about 50 species, many of which have been transferred from Eriocactus, Notocactus and Wigginsia.
Aloe, is a genus containing about four hundred species of flowering succulent plants. The most common and well known of these is Aloe vera, or "true aloe".
Succulents entered as miniatures include representatives from almost every family, and a list would be far too long to print.
Miniatures are defined differently for different shows. In most cases, the definition is a mature plant in a pot with an inside diameter less than three inches.
From northern Africa and islands close by. They produce succulent rosettes of waxy leaves, generally at the end of naked stems.
Cacti from the highlands of Bolivia and Northern Argentina. Coming from high altitudes.
A genus of at least 28 species of small clumping leaf succulents from South Africa.
Small cacti from Mexico and the Southwestern United States.