Combining the responses from Dennis in Cincinnati and Jim McKenney: "Lilium grayi may well be a relict species... it makes sense if they got pushed southward with the glaciations." In fact, when Lilium grayi was first discovered (and named for Asa Gray by the herpetologist Sereno Watson) some thought it was only a form of Lilium canadense. Lilium canadense in northern coastal North America and Lilium grayi are very distinct. But inland, Lilium canadense changes a bit: there is a widespread form called Lilium canadense var. editorum which looks like what you would expect to get if you crossed typical Lilium canadense and L. grayi. In fact, about fifty years ago that cross was done and sure enough the progeny looked like L. canadense var. editorum. That makes me think that Lilium canadense is "capturing" Lilium grayi: Lilium grayi exists only at the fringe of the range of L. canadense. Also, the plant illustrated in many early twentieth century publications as Lilium grayi is something else, probably a hybrid between L. canadense and L. grayi or an extreme form of L. canadense var. editorum. Jim McKenney Montgomery County, Maryland, USA, USDA zone 7, where winter returns tonight.