The putative intergeneric hybridization between Stansbury Cliffrose (Cowania) and Apache Plume (Fallugia) is found to be undocumented. Chromosome counts support reported base numbers for Cowania and Fallugia to be n = 9 and n = 14 respectively.
Baker, Marc A.; Pinkava, Donald J.; Parfitt, Bruce; and Righetti, Timothy
"On Cowania and its intergeneric hybrids in Arizona,"
Great Basin Naturalist: Vol. 44
, Article 14.
Available at: http://scholarsarchive.byu.edu/gbn/vol44/iss3/14