Large-flowered Trillium

One of the most well-known and popular spring wildflowers, Trillium grandiflorum puts on impressive displays in rich, mesic woodland.

For interesting reading, look into the way Trillium seeds are equipped with a little caruncle of oily material (known as an elaisome) that is attractive to ants. The ants collect the seeds, carry them away to the nest, eat the caruncles, and discard the seeds, possibly underground. Many plants do this - not just Trilliums.
Photographed at Bendix Woods County Park in St. Joseph County, Indiana, where this plant occurs by the thousands! http://www.sjcparks.org/bendix.html.