Toadshade most commonly has dark brownish-purple flowers, but the green form is not uncommon. Here we see it blooming by Saw Mill Run in Seldom Seen. Some botanists distinguish the green form as forma viridiflorum; others just say that sometimes Trillium sessile is green and nothing can be done about it. There are also intermediate forms with brownish-green or greenish-brown flowers.
For a description of the species, see the Trillium sessile reference page.