peat moss

noun

Also called bog moss. any moss, especially of the genus Sphagnum, from which peat may form.

such moss after it has been dried, used chiefly as a mulch or seedbed, for acidification.

Origin

1225-75 for earlier sense; 1870-80 for def 1; Middle English petemos (in placename) peat bog

British Dictionary definitions for peat moss

peat moss

noun

any of various mosses, esp sphagnum, that grow in wet places in dense masses and decay to form peat Also called bog moss See also sphagnum

peat moss in Science

peat moss
Any of various mosses of the genus Sphagnum, growing in very wet places, especially bogs, around the world. The leaves of peat moss have large dead cells surrounded by smaller living ones that contain chloroplasts. The walls of the dead cells are perforated and readily absorb water, up to 20 times their dry weight. The walls also contain phenol compounds that resist decay and have antiseptic properties. Peat moss releases hydrogen ions that increase the acidity of the water in bogs. Because of its ability to absorb liquids, peat moss is sometimes used as diaper material by traditional peoples and was once used in making bandages. Peat moss is now used primarily to increase the water-holding capacity of soil. Also called sphagnum. See more at bog.