Common Names
Pincushion Cactus, Arizona Fishhook Cactus, Small Fruited Pincushion

Habitat
Sandy or rocky desert terrain; often found growing in partial shade beneath a larger plant

Flowers
1 to 1.5 inches wide, pink, with white edges, light green stigma; sprouting from the body of the cactus between the tubercles. Fruits are long and narrow, to 1.5 inches long, red to red-orange when ripe

Description
lustering stems 2 to 3 inches wide, up to 8 inches tall. white to greyish radial spines lie flat against the body; sometimes there are several central spines, the longest of which is usually hooked

Comments
probably the most common pincushion cactus of central Arizona. Many specimens can be seen growing under creosote bushes on Tempe's "A" Mountain.

http://www.public.asu.edu/~camartin
Mammillaria grahamii (formerly Mammillaria microcarpa)
Common pincushion cactus, Graham's nipple cactus