Taxonomy: There has been a good deal of taxonomic discussion in recent years regarding some of the species in the Cupressaceae. This has resulted in (Smooth) Arizona Cypress being classified as Cupressus glabra, Callitropsis glabra, and more recently as Hesperocyparis glabra. As of 2024 Hesperocyparis (western cypress), (hesperus, -a, -um; Latin, of the west, western) is listed as the correct genus classification of this species by Plants of the World Online, World Flora Online, and the Gymnosperm Database. There is disagreement about this classification, with some scientists continuing to use Cupressus in preference to Hesperocyparis. For details, click on the Genus Hesperocyparis in the following link.