Prior to proper taxonomic investigation into the genus, many species within
Dudleya were variously classified as
Cotyledon,
Sedum and
Echeveria. The plants currently assigned to this subspecies were first treated taxonomically in 1903 by
Nathaniel Lord Britton and
Joseph Nelson Rose, who had been working on a revision of
Crassulaceae species in
North America, which included the creation of the genus
Dudleya, named in honor of a
Stanford University professor of botany
William Russell Dudley. At the time, Britton and Rose placed a specimen of this subspecies as
Dudleya parishii, a name now synonymous with
Dudleya lanceolata. In the years preceding his death in 1928, Rose had decided that the common
Dudleya of central Arizona represented an undescribed species, and produced a species description, which went unpublished due to his death. In 1934,
Conrad V. Morton authenticated Rose's description in the Desert Plant Life journal, creating
Dudleya collomiae. The species was named for Mrs.
Rose E. Collom, a botanist who collected the type specimen of
Dudleya collomiae. Despite the description by Rose, along with the creation of the genus
Dudleya many years prior, botanists such as
Thomas Henry Kearney and
Robert Hibbs Peebles kept it as a species of
Echeveria,
Echeveria collomae,
Marcus E. Jones as
Cotyledon saxosa, and
Phillip Munz included this species in the range of
Echeveria saxosa. It was not until the cytotaxonomic work by
Reid V. Moran and Charles H. Uhl finally cemented
Dudleya as distinct from
Echeveria and other Crassulaceae genera. == Distribution and habitat ==