Also known as white trillium or great white trillium. These were in the woods near Rocky Fork Creek on April 9, 2016. There is another white trillium called a snow trillium that only gets to 3.5 inches. Have to watch out for that one.
Again April 9, 2016 on rocky hillside near the Rocky Fork creek found many of these trilliums. Looks to be Trillium sessile (the toadshade, sessile-flowered wake-robin). Looks like this is not the purple trillium so the search will be continued.