The taxonomy—or categorization—of the four different kinds of Agave utahensis has changed over the years. And most of us still lean towards using the same taxonomy that Gentry used, including Agave utahensis subsp. utahensis var eborispina, and Agave uthaensis subsp. utahensis var nevadensis, generally shortened to Agave utahensis var eborispina and Agave utahensis var nevadaensis.

In 1871, German botanist George Engelmann first formally described Agave utahensis in a paper on samples gathered during a geological expedition.

In 1929, J.M. Greenman and E. M. Roush wrote about a sample that was submitted to them at the Missouri Botanical Garden: “…Critical comparison of these fragments and the specimens from southwestern Nevada with the type of A. utahensis shows… striking differences… warrant the recognition of this plant at least as a distinct variety…” They called the new variety Agave utahensis var nevadensis.

In 1943, Jay Pickney Hester—first to formally describe eborispina—called it Agave eborispina species nova, a new species, saying it “probably originated as a mutant from what appears to be a subspecies of A. nevadensis.“ But still referred to nevadensis as Agave utahensis var. nevadensis.

In 1949, Susan Delano McKelvyana—first formally describing kaibabenisis—also called it Agave kaibabensis species nova. She noted: “At first glance the plants were thought to be Agave utahensis Engelm., in colossal form… But examination disclosed marked differences in the individual leaf, the leaf-rosette, to some extent in the inflorescence, and, important, in the habit of the plant.”

In 1982, in his seminal Agaves of Continental North America, Howard Scott Gentry used the names: Agave utahensis subspecies kaibabensis, Agave utahensis subspecies utahensis, Agave utahensis subspecies utahensis var eborispina, and Agave utahensis subspecies utahensis var nevadensis.

I’m sure there have been other changes, but the currently agreed-upon organization of the species happened just a few years ago.

In 2022, Fritz Hochstatter reorganized the species taxonomy, labeling them: Agave utahensis subsp. kaibabensis, Agave utahensis subsp. utahensis, Agave utahensis subsp. nevadensis, and Agave utahensis subsp. eborispina. This is the most recent accepted taxonomy, and was published in the Cactus Adventures International Journal.

I don’t agree with this change (elevating eborispina and nevadensis to their own subspecies), as I’ve seen plenty of utahensis, eborispina, and nevadensis transitional forms, and think of those three as less distinct than subspecies. But for the sake of clarity, this is the taxonomy I’ll be using when writing about utahensis going forward.

The Taxonomy of Agave Utahensis

Is Agave utahensis a succulent?