The Fawn Lily doesn't die after blooming. I haven't found any information saying they die after blooming? Do you have a link that talks about it?
I know the foliage dies back after blooming, like many of our spring blooming bulbs do. : )
There are a number of different species of Erythronium:
http://en.wikipedia.org/wiki/E...
How fascinating. I love the pink one they show in the wikipedia link.