Walking Fern, a native species, has been added to the USWildflowers database (05/04/2013.) Scientific name is Asplenium rhizophyllum.  It  is also known by the common name American Walking Fern, because there is a similar Asian species, although it is not found in the United States.  Photo below was taken in the Virgin Falls State Natural Area of eastern Tennessee on March 8, 2013.  Go to the Walking Fern detail page for more photos and information.

Walking Fern, American Walking Fern – Asplenium rhizophyllum