Variable spineless cactus with white flecks and large yellow flowers, from northeastern Mexico. It usually has 5 ribs. Found in San Luis Potosí, Nuevo León, and Tamaulipas. Several varieties have been described, though not all may be currently recognized.

Lots of interesting cultivars have been selected and named. Versions with fewer than 5 ribs are sometimes given names like quadricostatum (4 ribs) or tricostatum (3 ribs). Versions lacking the surface flecks are sometimes given the name nudum. These names seem to exist mainly to sell plants, given they are more or less normal forms of the plant. The former var. columnare has taller stems (at least in proportion to their width) and exists on a continuum from more or less normal width to greatly reduced width (the latter often accompanied by branching).

This cactus looks a lot like A. coahuilense (which was formerly a subspecies or variety) but it exists in a separate area a few hundred kilometers to the southeast, and there are differences in fertility, flowers, fruit and seeds. The two species do not apparently hybridize. The flowers are yellow (without a reddish center). The fruit is greenish (not pinkish) and dehisces apically (not basally).

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