Gentry (1982) considers the wild populations of Agave americana ssp. protoamericana in the Sierra Madre to be the original source for the Agave americana complex. This is a highly variable species, with its offsetting glaucous blue-green, medium- to-large rosettes. The leaves tend to have upturned tips with significant terminal spines and fierce marginal spines. These plants are seedlings in 4-inch pots.
