Fly Poison, a native species, has been added to the USWildflowers database (08/20/2011.) Scientific name is Amianthium muscitoxicum.  It is also known by the common name Stagger Grass.  Photo below was taken in the Great Smoky Mountains National Park on Aug 1, 2011.   Go to the Fly Poison Detail Page for more photos and information.

Fly Poison, Stagger Grass – Amianthium muscitoxicum