Mammillaria muehlenpfordtii Foerst.

Clustering by dichotomous branching, body globular, to 10(-15) cm wide. Tubercles obscure. Axils bristly. Central spines 4, 3-4 mm long, lower to 15(-35) mm long, yellowish. Radial spines 40-50, to 4 mm long, white, bristle-like. Flower deep pink, 1-1.5 cm long and wide. Fruit red.

C Mexico

Source: Thompson, A, ; Forbes, S.; Spencer, R. (1997). Cactaceae. In: Spencer, R.. Horticultural Flora of South-eastern Australia. Volume 2. Flowering plants. Dicotyledons. Part 1. The identification of garden and cultivated plants. University of New South Wales Press.

kingdom Plantae
phylum   Tracheophyta
class    Magnoliopsida
superorder     Caryophyllanae
order      Caryophyllales
family       Cactaceae
genus        Mammillaria Haw.