Research and Conservation in Southern Sonora, Mexico
Mammillaria standleyi (pitahayita, pincushion cactus)
syn: Mammillaria canelensis, M. hertrichiana, M. miegiana, M. montana, M. movensis, M. sonorensis, M. tesopacensis, & several more
It is still unclear whether this variable complex is one or several species. There is so much variation in characters such as spination, woolliness, and flower color that most authors choose to lump them together until further studies are done. Whatever it's name(s), this plant is nearly endemic to the Rio Mayo region.
 Mammillaria standleyi in the Sierra de Alamos, Sonora. Photo: Mark Dimmitt |
 Mammillaria standleyi from the Sierra de Alamos, Sonora. Photo: Mark Dimmitt |
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| Mammillaria standleyi in the Sierra Canelo above San Bernardo, Sonora. This population was described as M. canelensis. Photos: Mark Dimmitt | |
The globose, often clustering, plants can be found on rock outcrops in tropical deciduous forest and oak woodland.