William A. Weber is Professor and Curator Emeritus of the Herbarium, University of Colorado Museum of Natural History and Fellow of the Linnean Society of London. A highly acclaimed author with over 65 years of botanical experience in Colorado, he has written extensively on the flora of Colorado, including Rocky Mountain Flora (UPC 1991) and A Rocky Mountain Lichen Primer (with James N. Corbridge, UPC 1998) and Bryophytes of Colorado (Pilgrims Process 2010)and Colorado Flora (UPC 2001) with Ronald Wittmann. Ronald C. Wittmann is Museum Associate, University of Colorado Museum of Natural History. He became an expert on the flora of the state collaborating closely with Dr. William Weber over the past 30 years in the field and laboratory. Books include Colorado Flora (UPC 2011), Catalog of the Colorado Flora (UPC 1992), and Bryophytes of Colorado (Pilgrims Process 2010).