Mammillaria crucigera Mart.

Solitary or eventually clustering, body elongating, 4 cm wide. Tubercles close set. Axils woolly. Central spines 4(-5), 2 mm long, yellowish. Radial spines 24, 2 mm, white. Flowers deep pinkish purple, small. Fruit red.

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.