This species is widely distributed in Mexico, central America, into northern South America, and also in the Caribbean. Once known as M. ruestii ssp. albicanus, probably for the light yellow body topped with the white cephalium, this plant also features white spines. Subspecies caesius has mostly straight, not curved, spines that are stouter. The flowers are reddish-purple. These plants are seedlings in 3-inch pots.
