Numbers refer to chromosome numbers.
J.H. Hunziker, R.A. Palacios, L. Poggio, C.A. Naranjo, and T.W. Yang. Geographic distribution, morphology, hybridization, cytogenetics, and evolution. p. 10 - 47 IN T.J. Mabry, J.H. Hunziker, and D.R. DiFeo, Jr. 1977. Creosote bush biology and chemistry of Larrea in the new world deserts. Dowden, Hutchinson & Ross, Inc. Stroudsburg, Penn.
Hunter, K. L., J. L. Betancourt, B. R. Riddle, T. R. Van Devender, K. L. Cole, and W. G. Spaulding. 2001. Ploidy race distributions since the last glacial maximum in the North American desert shrub, Larrea tridentata. Global Ecology & Biogeography 10:521-533.