Tall Ironweed (Vernonia gigantea) in an open field at Big Hollow Recreation Area in Des Moines  County, Iowa.

Details: 

Canon EOS 10D,  shutter 1/250second, aperture f9.5, ISO 200, Canon EF 100 mm macro lens.

Selected References:

Thieret John W, Niering William A, and Olmstead Nancy C. National Audubon Society Field Guide to North American Wildflowers, Eastern Region. New York: Alfred A. Knopf, Inc. Plate 608, P 422.

USDA-NRCS. "Plant profile for Vernonia gigantea."  The PLANTS Database (http://plants.usda.gov/ ). National Plant Data Center, Baton Rouge, LA 70874-4490 USA. 2004. < http://plants.usda.gov/cgi_bin/topics.cgi?earl=plant_profile.cgi&symbol=VEGI > (1 Aug. 2005).