Asteraceae
Locklear, J. 1989. Parthenium alpinum and its relatives in Colorado. Aquilegia 13(3):10-11.
Lowrey, T., and P.J. Knight. 1994. Townsendia gypsophila (Compositae [Asteraceae]): a new species from northern New Mexico. Brittonia 46(3): 194-199.
U.S. Fish and Wildlife Service (USFWS). 1987. Final rule to determine Cirsium vinaceum (Sacramento Mountains thistle) to be a threatened species. Federal Register 52(115): 22933-22936.
Heidel, B. and J. Handley. 2002. Draft: Bolophyta alpina (Wyoming feverfew) Conservation Assessment. Wyoming Natural Diversity Database. University of Wyoming. Laramie, Wyoming.
Yarborough, S. C. and A. M. Powell. 2006. Perityle. In : Flora of North America, eds. 1993+. Flora of North America North of Mexico. 12+ vols. New York and Oxford. Vol. 21, pp 317-334.
U.S. Fish and Wildlife Service (USFWS). 1985. Proposal to determine Hymenoxys texana to be an endangered species. Federal Register 50(44): 9095-9097.
Nesom, G. L. 1991. A new species of Erigeron (Asteraceae: Asterae) from Northwestern New Mexico. Phytologia 71(5): 416-419.
Spellenberg, R., and P. Knight. 1989. A new species of Erigeron (Asteraceae: Astereae) from central New Mexico. Madrono 36(2): 115-121.
Nesom, G. 1978. Erigeron hessii sp. nov. and Erigeron kuschei Eastwood (Compositae), two closely related narrow endemics from the southwestern United States. Brittonia 30(4): 440-446.
Heiser, C.B., Jr., with D.M. Smith, S.B. Clevenger, and W.C. Martin, Jr. 1969. The North American sunflowers (Helianthus). Memoirs of the Torrey Botanical Club 22(3). 218 pp.