FEATHER MOSS

also called Plume Moss, or Boreal Forest Moss (Ptilium, formerly Hypnum, crista-castrensis), widely distributed plant of the order Bryales that forms dense, light-green mats on rocks, rotten wood, or peaty soil, especially in mountain forests of the Northern Hemisphere. The erect stem of a feather moss has a feather-like, or frondlike, appearance. The leaves, with their curving, hooklike tips, are often more than two millimetres (1/10 inch) long.