This is Astrophytum myriostigma v nudum cv khoyo, kikou. I degrafted this cacti last autumn and under rooting currently.
This cultivar has two specific characters. One is khoyo, turning body color to red in autumn and spring and returning to green in summer when the cacti was juvenile. This cacti is too old to turne the color but it is remained some character. The other is kikou, turning body shape as like tortoiseshell when the cacti was matured. This cacti has shown the kikou character.