Neckera pennata

Neckera pennata (flat feather moss) growing at the base of a black ash tree in a swamp. The leaves of Neckera pennata have a rippled appearance produced by transverse undulations.

This moss is an indicator of old hardwood forests. "Growth of Neckera pennata, an epiphytic moss of old-growth forests." Ingerpuu, Vellak, and Möls. The Bryologist 110(2), (1 June 2007).

"Neckera pennata is recognized by its immersed sporophytes, undulate, acute to broadly acute leaves, and paraphyllia absent or scarce. The leaves have very few alar cells." http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=200001899