Their home is in the South American Andes. They are not big, up to only 15 cm diameter after many years in cultivation. They are very very prickly as being armed in thin but stiff, yellow to brown, greying with age numerous spines. You can expect (after 5 to 10 years from seed) white, pink, light purple or yellow flowers. Of the 14 species described so far only several are considered good, some extreme-sport-scientists maintain there are only two of them (whereas others say the whole genus belongs to Echinopsis). You will not encounter problem while growing them provided they are provided (yeah, I know) with a lot of sun in the growing season and really cold (2-5-10ºC) and dry winter. Potting mix, slightly acid, should be very porous, so add a lot of sand or pumice or anything of that kind.