history

Weber, W.A. 1987. Colorado flora: Western slope. Colorado Associated University Press. Boulder. 530 pp.

• morphology
• nomenclature
• rara
• distribution
• HABITAT
• history

Benson, L. 1982. The Cacti of the United States and Canada. Stanford University Press, Stanford, California. 1044 pp.

Flora of North America Editorial Committee. 1993b. Flora of North America north of Mexico. Vol. 1. Introduction. Oxford Univ. Press, New York.

• vegetation
• NORTH AMERICA
• Paleobotany
• vascular plants
• Geography
• Geology
• history

Miller, L. D. and F. M. Brown. 1981. A Catalogue/Checklist of the Butterflies of America North of Mexico. The Lepidopterists' Society Memoir No. 2, Sarasota, Florida. 280 pp.

• taxonomy
• checklist
• history
• butterfly