References
USDA-NRCS.2004. The plants Database.
(http://plants.usda.gov/plants). National Plant Data Center, Baton
Rouge, LA 70874-4490 USA.
Ladd, Doug. Tallgrass
Prairie Wildflowers, A Field Guide. Guilford: The Globe Pequot
Press, 1995.
USDA-NRCS.2001. The Plants
database, Version
3.1 (http://plants.usda.gov). National Plant Data Center, Baton
Rouge, LA 70874-4490 USA.
Copyright. 2002-2003. By john Hilty All Rights Reserved. www.shout.net/~jhilty/plantx/pr_queenx.htm