The photo is a degrafted Ariocarpus retusus v furfuraceus cv Suguri cauliflower.
A around 15 mm length of pereskiopsis stock is remained and I assume roots come out from the stock.
Since Pereskiopsis is not a parmanent stock, it will die in 2~3 years. Own roots will come out from the scion at that time. The plant is 2 years old, 8 cm diameter.
It was in flwer last autumn.