Cactus / ritteri

A degrafted Aztekium ritteri was in flower yesterday.
I propagated this one from pups grafting onto Pereskiopsis.
Although pups of ritteri are quite hard, it is possible to graft onto Pereskiopsis without  any pressure.
I degrafted this one 2 years ago with a short stock of the Pereskiopsis.
The plant has still relied on the short stock, no development of roots from the scion.
It is very small, 3 cm diameter.