It has been suggested to me this is a member of the genus Echinopsis. It was given to me in 1995 as a 6” high columnar cactus. It was very boring and nothing changed for three years until one day it began growing little round daughters along it’s flanks. Soon the original column vanished under them. There has never been a flower so I have no real clue to it’s identity. Please leave your comment if you think you know. Even if it never blooms it is my old friend and it will be with me until one or the other of us meets our end. It has achieved such complexity that is has become a landscape in itself. The pot is about 26cm wide. It is a terra cotta saucer I drilled drainage holes in.