The reference keys used for plant species identification are Michigan Flora, the three part series by Voss (1972, 1985, and 1996); and, Manual of Vascular Plants of the Northeastern United States and Adjacent Canada by Gleason and Cronquist (2nd edition, 1991).
Supporting references used along with the keys include:

• The Illustrated Companion to Gleason and Cronquist’s Manual by Holmgren (1998)
• Michigan Trees by Barnes and Wagner (1981, 2004)
• Weeds of the Northeast by Uva, Neal, and DiTomaso (1997)
• Michigan Flora Online. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. (http://michiganflora.net/home.aspx)
• The USDA Plants Database (http://plants.usda.gov/java/)
• Flora of North America (http://fna.huh.harvard.edu/)

The source used for current plant nomenclature is Michigan Flora Online. If a species is not listed in Michigan Flora Online, the USDA Plants Database will be the source for current nomenclature. When nomenclature differences occur in Great Lakes Bioenergy Research Center (GLBRC) plant data from Wisconsin, the alternate name will be displayed along with the KBS name.

Past references also included Gray’s Manual of Botany by Fernald (8th edition, 1950); and, Field Guide to the Grasses, Sedges, and Rushes of the United States by Knobel (1980).