Rock firmoss

The rock firmoss grows throughout the Appalachian province of the eastern United States, but is rare east of the Appalachians, being most common in a north-south belt along the western plateau area. This firmoss grows only on or over rock, and requires cool, moist, shaded, acid spots. It is a beautiful sight growing over boulders and outcrops. It is often confused with the shining firmoss[?], Huperzia lucidula, which range it largely shares, but uniformly has eight-ranked leaves, while lucidula largely has six-ranked leaves and grows in seeps, generally not on rocks.