Hello I'm Looking for North America Native Lily Seed, I'm building a collection. Can trade with L. Canadense var. Flavum Pierre ,Quebec
Gardens North http://www.gardensnorth.com/site/index.htm has seeds of native to NA Lilium columbianum and two kinds of Lilium philadelphicum. Pacific Rim Native Plant Nursery http://www.hillkeep.ca/ has Lilium canadense var. coccineum, Lilium pardalinum, Lilium parvum(at least zone 6) To find more I advise you to search the Net for nursery catalog native lilium seed or similar combination of words.
Prairie Originals has plants of Lilium philadelphicum http://www.prairieoriginals.com/prairiewildflowers2.php#RED_LILY I don't see seed listed, but if you contact them, I'm sure you could either get some bulbs or seeds.