Convallaria majuscula
Until now, I did not know that Lily of the Valley grows wild in the Appalachian Mountains! The form that most of us know, the garden variety, was imported from Europe and then popularized in American gardens. But this species–the wild one- is a few degrees different, and it is appropriately called American Lily-of-the-Valley.
First of all, unlike the common cultivar, American Lily-of-the-Valley is not as likely to be found growing in dense colonies. You will probably just find a couple of plants at a time in any given area. The leaves of the plant are taller than the garden variety too (10-12 inches vs. 6 inches), and the flowering stems are shorter. It is harder to see the flowers of the native form, because they sit well below most of the leaf mass. That said, the white, bell-shaped flowers are identical, and they are just as pretty and fragrant as the garden cultivar!
This is a perennial plant that occurs in a limited range in the mid-Atlantic . It blooms between May and June.
It is not uncommon to find the escaped, cultivated form in the woods too, especially around old home sites. Again, the cultivated form (Convallaria majalis) has shorter leaves (6 inches) and the flowers bloom on longer stems that are held above the leaves.
Don’t try eating the beautiful leaves of either form! They are poisonous!
Note: Some people call the Canada Mayflower by the name Wild Lily-of-the-Valley. Check it out for comparison.
Here’s a gallery of the American Lily-of-the-Valley:
VIRGINIA WILDFLOWERS 
This is a wonderful article. I removed most of the exotic one. Do you know if American one is native to NJ? I searched fir a native range map, but no luck. Thank you!
Thank you for this article. My plants came from my Moms’ border. She received them from family who came to this area of Virginia around 1900 from Nebraska. I received Peony plants that came from them which were brought also. My Lily of the Valley are very slow multipliers. I have them in 4(four) different areas of the yard and they are growing in 4(four) different micro climates. I have some that are topping out at 14(fourteen) inches tall. The top of the leaf is shiny and the underside is matte. The underside has pronounced ribs. A single plant will grow and not send out a runner for at least 2(two) years. The runner will be about 12(twelve) inches from the original plant.I am leaning on the fence towards these being an American variety.