Is there any doubt as to why this Mammillaria spinosissima is called the Red-Headed Irishman? The dark, copper colored spines definitely have the look of redhead with a brush cut.
The spines on this specimen are some of the reddest I've seen of this species. As it gets older, it will become columnar and the spine color may be less pronounced, but it should always retain the reddish hue. The spine color of the M. spinosissima can vary, depending on the subspecies, from a translucent white (M. spinosissima ssp. pilcayensis) to a yellowish brown (M. spinosissima ssp. tepoxlana.) The spines are very soft and flexible, and one can brush against them without much fear.
Originally from Mexico, the M. spinosissima needs light shade and winter warmth in Phoenix. In spring, it produces dark pink flowers in the typical ring pattern of the Mammillaria genera. The subspecies have flowers that range from magenta to fuchsia.
This past spring, members of our local Cactus and Succulent Society were asked to bring in at least five plants for the annual show. Since I have so few mature or truly exotic plants, I almost decided to skip the competition, but at the last minute, I picked out five of my nicest looking commonplace cacti, hauled them down to the show and, lo and behold, this M. spinosissima won a First Place ribbon for its division. I think it what did it was the exceptionally red spines.