Sphagnum in establishment of new populations in disturbed habitats and on islands. Decayed, dried sphagnum moss has the name of peat or peat moss. This is used as a soil conditioner which increases the soil's capacity to hold water and nutrients by increasing capillary forces and cation exchange capacity. This is often necessary when dealing with very sandy soil, or plants that need increased or steady moisture content to flourish. A distinction is sometimes made between sphagnum moss, the live moss growing on top of a peat bog, and 'sphagnum peat moss' (North American usage) or 'sphagnum peat' (British usage), the
Moss in cities. Examples would be "Rhytidiadelphus squarrosus", a garden weed in Vancouver and Seattle areas; "Bryum argenteum", the cosmopolitan sidewalk moss, and "Ceratodon purpureus", red roof moss, another cosmopolitan species. A few species are wholly aquatic, such as "Fontinalis antipyretica", common water moss; and others such as "Sphagnum" inhabit bogs, marshes and very slow-moving waterways. Such aquatic or semi-aquatic mosses can greatly exceed the normal range of lengths seen in terrestrial mosses. Individual plants or more long are common in "Sphagnum" species for example. Wherever they occur, mosses require liquid water for at least part of the year to complete