Yellow Trillium

I found this yellow trillium near Greebriar Cove of the Smoky Mountains on April 11, 2006. Like all trilliums, this plant has structures in sets of three: three leaves, three sepals, and three petals. This is one of FIVE trillium species I found and photographed in the Smokies this spring.
I found this species listed in a wildflower book called, Wildflowers of the Smokies, which I purchased at the Sugarlands Visitor Center in the Smokies, but is also available on their website. This book refers to this plant as yellow trillium or Trillium luteum. The flower has a lemony scent.
This trillium reminds me of Trillium sesile, which I used to find back in the forests of eastern Iowa. Back in those days, this was the one trillium I knew well, but its flower is maroon and not yellow. However, like this trillium, my familiar trillium back in Iowa had mottled leaves, and a flower sitting directly at the top of the leaves (without a stalk or stem).