Found this plant northeast of Sells, Arizona. My first thought was M. grahamii, but I'm not used to it with yellow spines, and also, I'm not all that familiar with other AZ mamms. Nice old cactus.
yellow-spined Mammillaria
Re: yellow-spined Mammillaria
Mammillaria mainiae, and a nice fat clump of it too! Love that plant. Was only aware of it from southeast of Sells, so it is interesting to me that this one was north. It is one of those Sonoran species that barely enters the US, just like Cory recurvata, etc.
peterb
peterb
Zone 9
Re: yellow-spined Mammillaria
Cool. Thanks. I don't think I would have figured that one out on my own. I'm always happy to help extend the habitat range of a cactus.