Xerophyte

Habit

Usually solitary in habitat, but occasionally branching basally in cultivation.

Note

Seems to be a pretty variable plant you might get some other names which are effectively the same plant.... and also not sure all plants identified as this are really this.

Flowers

Whitish to rose pink, deepening to purple in the centre.

Spines

Usually carries 3 spines, but sometime 5 or 7.

Ribs

13-15 barely obvious with rounded and pointed tubercles.

Stem

Flattened to globular, green to coppery-brown, spherical up to 10 cm in diameter.