Cylindropuntia xviridiflora (Cactaceae) is a rare plant endemic to Santa Fe County, New Mexico. It is currently assumed to be a hybrid of two more-common species, C. imbricata and C. whipplei. I conducted botanical surveys in key areas of Canyon de Chelly National Monument, Arizona, and Santa Fe County, New Mexico, with the aim to assess possible C. ×viridiflora occurrence. During these surveys I found and described three novel populations of what appeared to be C. ×viridiflora in Canyon de Chelly. In this paper, I address the taxonomic relationships among these novel populations, populations of C. ×viridiflora documented from Santa Fe County, and their putative parental taxa. To do so, I collected morphometric data on fifteen characters from Cylindropuntia individuals in Canyon de Chelly and Santa Fe County, and I conducted multivariate analyses (Cluster and PCA) to elucidate the degree of morphologic similarity between them. The results suggest that the novel populations from Canyon de Chelly are more closely affiliated to C. ×viridiflora from Santa Fe than they are to either C. whipplei or C. imbricata.