Coryphantha elephantidens (Figure 1) is one of the most distinctive of the several dozen species in this genus. The stems are three to four inches in diameter, and offset to form clusters of up to a dozen or more heads (Figure 3). (In The Cactus Family Anderson says the stems can be nearly 8 inches in diameter, but I have never seen any even close to this.) As the specific epithet describes, the stems have very large tubercles. The few short stout spines don’t conceal the shiny green cuticle.
The two-inch pink flowers are not borne in masses as in many cacti. They appear one or two at a time per stem, every few days for about three months from September to November (Figure 2). The subspecies C. e. greenwoodii and C. e. bumamma have yellow flowers.
The species occurs in Michoacan and Morelos, Mexico. It’s winter hardy anywhere in southern Arizona. Grow it in any well-drained succulent medium, in light shade. Water little in winter, and also keep it on the dry side during extremely hot weather to avoid rot.