Portlethen Moss millennia of evaporation, further intensifying the soil acidity, fueled by organic matter decaying, with little drainage outlet. A layer of sphagnum moss would have developed at the benthic level of the bog, and additional sphagnum layers floated in mats atop the bog. At an intermediate level of evolution, thick peat layers formed from decay and carbonisation of the rotting sphagnum. Generations of carex and juncus flourished, leading to further decay of these materials and eventual heightening of the organic mass. Finally, secondary vegetation took root in the spongy sphagnum mats adding greater biomass to the bog.In some cases the heavy
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