Ferocactus
(Photo: Wen-Chung Fan)
fans@igc.org
http://go2.163.com/cactusfan

I still have this white Ferocactus.   It is smaller than normal form, but it can get pretty big. I have seen them as big as 10cm, but at that size, they are not very pretty... http://go2.163.com/cactusfan/whitefero.jpg