Muenscher's Keys to Woody Plants. An Expanded Guide to Native and Cultivated Species by Edward A. Cope. Cornell University, 2001 location

How to Know Western Australian Wildflowers - a key to the flora of the extratropical regions of Western Australia Pt II dicotyledons by BJ Grieve. 2nd ed. University of Western Australia Press and the Wildflower Society of Western Australia Inc.1998 location

The Identification of Flowering Plant Families including a key to those native and cultivated in north temperate regions by PH Davis and J Cullen. 3rd ed. Cambridge University Press1989. location

Manual of Vascular Plants of Northeastern United States and Adjacent Canada by HA Gleason and A Cronquist. New York Botanical Garden 1991 location

Vascular Flora of Illinois: a field guide by Robert H. Mohlenbrock 4th ed. 2014 paper ed. location