A type of rather luxuriant growing moss, normally an inhabitant of boggy ground and much used when dried as an ingredient in potting mixes, especially for orchids. Live plants often grow from spores in the dried material, and are welcomed by orchid growers as a sign that conditions are right.
Moss of the genus Sphagnum, which grows in vast masses in bogs in cooler areas of the world, creating acid conditions in the water which inhibits decay when the lower parts of the moss eventually die, resulting in deep deposits of the dead moss (see peat). The dead moss is very spongy and can absorb large quantities of water; it is much used when dried as an ingredient in potting mixes, especially for orchids. Sphagnum often appears to come back to life when kept wet, but this may be due to the growth of green algae among its leaves.