Birdsfoot trefoil or birdsfoot deervetch (Lotus corniculatus) found at Big Hollow Recreation Area in Des Moines County, Iowa (top) and Geode State Park in Henry County (bottom). The plant is several inches tall and is commonly seen in fields and along roadways.

Details: 

(Top)  Canon EOS 10D,  shutter 1/180second, aperture f8, ISO 100, Canon EF 100 mm macro lens.

(Bottom)  Canon EOS 10D,  shutter 1/180 second, aperture f22, ISO 100, Canon EF 100 mm macro lens, Canon MR-14EX ring 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 340, P 539.

USDA-NRCS. "Plant profile for Lotus corniculatus L."  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=LOCO6 > (26 June 2005).