Friday fabulous flower - Trillium whatever

A few years ago TPP got a bargain bag (and gardeners love bargains) of 6 "white" Trillium rhizomes.  So there was no illusion about knowing what was in the bag.  Actually at least 3 species, 3 T. flexipes (locally a fairly common white flowered species), T. erectum (not white flowered, shoots coming up behind this plant), and the rather lovely plant shown above (also not white-flowered). Was there a 6th plant?  Don't think so. But what grows here?  TPP's first thought was T. sessile, but the plant has grown up a bit now and the flower is decidely larger, longer petalled, and has sepals colored almost as darkly as the petals.  Hmm. Now the most likely identification is T. cuneatum.  It also looks like T. kurabayashii from N. Calif. & Oregon, which seems rather unlikely just based on geography, but since the location of origin is unknown, it is possible.  However it is a quite handsome plant no matter what.  Do others want to weigh in on the identification of this non-white, sessile-flowered, mottled-leaf Trillium?  But hey, what a bargain!  5 Trilliums, 3 species!