White Snakeroot (Ageratina altissima) or (Eupatorium rugosum) growing in a wooded residential area in Des Moines county, Iowa. This plant is poisonous and may enter the human food chain through cow's milk.

Details:  Canon EOS 10D,  shutter 1/250 second, aperture f8, ISO 400, Canon EF 100 mm macro lens, no flash

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 154, P 390.

USDA-NRCS. "Plant profile for Ageratina altissima."  The PLANTS Database (http://plants.usda.gov/ ). National Plant Data Center, Baton Rouge, LA 70874-4490 USA. 2004. <http://plants.usda.gov/cgi_bin/plant_profile.cgi?symbol=AGALA > (20 Sep. 2004).