Devon Wildlife Trust There are numerous species of Sphagnum Moss that look very similar, so are usually grouped together as 'Sphagnum' for easy description. These 'Bog-mosses' form the amazingly multi-coloured, 'living carpets' found in wet places like peat bogs, marshland, heath and moorland. They grow from spores that are produced in fruiting bodies called capsules. When seen up close, they are very beautiful, but they also play an important role in the creation and continuation of peat bogs. They hold water in their spongy forms long after the surrounding soil has dried out, providing essential nutrients and helping to prevent the decay of dead plant material. It is this organic matter that gets compressed over hundreds of years to form peat.
How to Identify
There are at least ten species of Sphagnum Moss in the UK, which are very difficult to tell apart. These species range in colour from red and pink, to orange and green. Sphagnum Moss plants are very small, but they grow closely together, forming spongy carpets; 'hummocks' are even created when the mosses grow to form large mounds up to a metre high.
Woodland Trust Types of moss in the UK: what they are and where to find them
Sphagnum species are more common in bogs, moors and marshes, but sometimes also appear in damp woodland. There are around 30 different species of sphagnum in the UK.
Peat is formed mainly of sphagnum moss. Peatlands are a unique habitat in their own right and a very important store of carbon. Sphagnum is amazingly absorbent and has antiseptic properties too – in the past it has been used instead of nappies and to dress wounds.
Photo: Derek Harper https://www.geograph.org.uk/photo/6654283
Devonshire Association The Botany Section was founded in 1908 to promote the study and enjoyment of Devon’s wild plants, including bryophytes (mosses), lichens and fungi.
Plantlife: Dartmoor Important Plant Area
In wetter spots, cross-leaved heath and purple moor grass grow and where bog develops plants like hare’s-tail cotton-grass, cross-leaved heath, round- leaved sundew and bog asphodel can be found along with a multitude of sphagnum mosses and other mosses and liverworts. In the valley bottoms, bogbean and pale butterwort thrive along with many different sedges.
Plantlife: Exmoor & the Quantock Hills Important Plant Area
In summer the moorlands turn pink with heather, bell heather and cross-leaved heath. Bogs and mires abound with wonderful plants like sphagnum mosses, lesser skullcap, bog pimpernel, bog asphodel, ivy-leaved bellflower and cranberry, along with insectivorous round-leaved sundew and pale butterwort.
Royal Horticultural Society: Peat Policy
The RHS has long been a force for change and we share public concern about the damage peat extraction does to our natural environment; we will continue to push for a fundamental reappraisal of how peat is used in horticulture.
Harnessing the expertise of RHS scientists, horticulturists and members is important to us. It ensures that we can act with precision and passion on the issues facing gardeners, growers and the environment.
Everyone at the RHS is passionate about improving our communities through gardening and plants. We know all too well how greening Britain will help us deliver improved outcomes for people’s physical, mental and social wellbeing, and how it will help us tackle climate change, safeguard wildlife and improve our environment.
National Biodiveristy Network Sphagnum
Wikipedia Sphagnum is a genus of approximately 380 accepted species of mosses, commonly known as "peat moss" though they are different as peat moss has a more acidic pH level. Accumulations of Sphagnum can store water, since both living and dead plants can hold large quantities of water inside their cells; plants may hold 16 to 26 times as much water as their dry weight, depending on the species. The empty cells help retain water in drier conditions.
Hence, as sphagnum moss grows, it can slowly spread into drier conditions, forming larger mires, both raised bogs and blanket bogs. Thus, sphagnum can influence the composition of such habitats, with some describing sphagnum as 'habitat manipulators'. These peat accumulations then provide habitat for a wide array of peatland plants, including sedges and ericaceous shrubs, as well as orchids and carnivorous plants.
Sphagnum and the peat formed from it do not decay readily because of the phenolic compounds embedded in the moss's cell walls. In addition, bogs, like all wetlands, develop anaerobic soil conditions, which produces slower anaerobic decay rather than aerobic microbial action. Peat moss can also acidify its surroundings by taking up cations, such as calcium and magnesium, and releasing hydrogen ions.
Under the right conditions, peat can accumulate to a depth of many meters. Different species of Sphagnum have different tolerance limits for flooding and pH, so any one peatland may have a number of different Sphagnum species.
Individual peat moss plants consist of a main stem, with tightly arranged clusters of branch fascicles usually consisting of two or three spreading branches and two to four hanging branches. The top of the plant, or capitulum, has compact clusters of young branches. Along the stem are scattered leaves of various shapes, named stem leaves; the shape varies according to species. The leaves consist of two kinds of cells: small, green, living cells (chlorophyllose cells), and large, clear, structural, dead cells (hyaline cells). The latter have the large water-holding capacity.