morphology
Hall, E. R. 1981a. The Mammals of North America, second edition. Vols. I & II. John Wiley & Sons, New York, New York. 1181 pp.
Luer, C.A. 1975. The native orchids of the United States and Canada excluding Florida. New York Botanical Garden. 361 pp.
Needham, J.G. and M.J. Westfall, Jr. 1954. A Manual of the Dragonflies of North America (Anisoptera). University of California Press, Berkeley, California. 615 pp.
Hitchcock, A.S. 1951. Manual of the grasses of the United States. 2nd edition revised by Agnes Chase. [Reprinted, 1971, in 2 vols., by Dover Publications, Incorporated, New York.]
Rickett, H. W. 1973. Wild flowers of the United States: Vol. 6 (3 parts). The central mountains and plains. McGraw-Hill Book Company, New York. 784 pp. + plates.
Cronquist, A., A.H. Holmgren, N.H. Holmgren, J.L. Reveal, and P.K. Holmgren. 1984. Intermountain Flora: Vascular Plants of the Intermountain West, U.S.A. Vol. 4, Subclass Asteridae (except Asteraceae). New York Botanical Garden, Bronx. 573 pp.
Pyle, R. M. 1981. The Audubon Society Field Guide to North American Butterflies. Alfred A. Knopf, New York, New York. 916 pp. + color plates.
Gould, F.W. 1975. The grasses of Texas. Texas A & M Univ. Press, College Station, TX. 653 pp.
Correll, D.S., and H.B. Correll. 1972. Aquatic and wetland plants of southwestern United States. 2 volumes. Stanford Univ. Press, Stanford, California. 1777 pp.
Linzey, A. V., and D. W. Linzey. 1971. Mammals of the Great Smoky Mountains National Park. The University of Tennessee Press, Knoxville, Tennessee. 114 pp.