New Nomenclatural Combinations and Types for Cactaceae in Utah

Evolution of the Xerocarpa clade (Opuntia; Opuntieae): Evidence for the Role of the Grand Canyon in the Biogeographic History of the Iconic Beavertail Cactus and Relatives

“…The number of areoles per cladode face and epidermal color can be useful for distinguishing O. basilaris var. heilii from other members of the clade, generally [ 33 ]. Likewise, we consider the infraspecific rank of subspecies more acceptable considering the geographic cohesiveness and presumed lack of interbreeding among populations of the two taxa with their non-overlapping distributions [ 64 ].…”

“…Several other varieties of O. basilaris also have been recognized by some, including O. basilaris var. heilii ( Figure 1 A) from southeastern UT [ 33 ], O. basilaris var. ramosa from western California [ 34 ], O. basilaris var.…”

“…erinacea [ 27 ]. Stock et al [ 31 , 33 ] also accept most infraspecific taxa, sensu Parfitt [ 27 ], as species, apparently based mostly on differences in ploidy and some cryptic morphological characters.…”

“…The origin of arid-adapted taxa may have been uniquely within western North American drylands, from where they further expanded their distributions outside of the area [5][6][7][8], or the expansion may have followed a south-some, including O. basilaris var. heilii (Figure 1A) from southeastern UT [33], O. basilaris var. ramosa from western California [34], O. basilaris var.…”

Opuntia macrocentra and Opuntia azurea: Two Attractive and Often Confused Taxa

“…Chromosome counts are extremely stable and important as a reliable indicator of species boundaries, sometimes more reliable than morphology. Obtaining chromosome counts is essential in resolving species in Opuntia (Stock et al, 2023) and must also serve as a preliminary step before DNA sequence studies to assure accurate identification of source. Gorelick (2023) stated that Opuntia macrocentra (Fig.…”