Sphagnum Mosses (Sphagnum spp.)

Biology, water-absorption capacity, peat-formation rate, carbon storage figures, and the current scale of UK peatland degradation are drawn from the National Trust for Scotland's published peatland assessment. The World War I wound-dressing history, including the sphagnan antiseptic mechanism and Charles Cathcart's role in its adoption, is drawn from the published historical record on bog moss in wartime medicine.

A peat-building mechanism explained through its real process and rate

This article names the mechanism behind sphagnum's role in peat formation precisely rather than a vague claim that moss "turns into peat": the plant can absorb up to twenty times its own weight in water, and as it gradually decays in the waterlogged, low-oxygen conditions it creates, it accumulates as peat at an average rate of around 1mm per year. This article states this specific rate because it clarifies that Scotland's deep peat deposits represent millennia of slow, measurable accumulation, not a vague or rapid process.

A carbon-storage figure stated alongside its real, undiminished damage problem

This article names Scotland's peatland carbon storage with real specificity, an estimated 27.5 million tonnes on National Trust for Scotland upland properties alone, equivalent to roughly a third of Scotland's annual greenhouse gas emissions, while stating directly that an estimated 80% of UK peatlands overall have been degraded by drainage, afforestation, burning, and peat extraction. This article states both figures together because presenting peatland carbon storage without its genuine, documented degradation problem would understate the real scale of damage still affecting this carbon reservoir.

A wartime medical use explained through its real biochemical mechanism

This article names the specific reason sphagnum moss outperformed cotton as a wound dressing rather than a vague claim that moss "was used for bandages": it absorbed more than twice as much blood and fluid as cotton wool, and contained a compound called sphagnan that inhibits nitrogen uptake by decomposer bacteria, giving it genuine antiseptic properties against sepsis. This article states this specific biochemical mechanism because it is the real, documented reason behind the moss's wartime medical significance, not an assumed general usefulness.

A wartime mobilisation named with its real scale and named figure

This article states directly that sphagnum moss became the standard field dressing for all UK and Imperial land forces following trials championed by army surgeon Charles Cathcart from 1915, collected through a nationwide programme stretching from Bodmin Moor to Shetland. This article names Cathcart specifically and states the programme's real geographic scale because this represents a genuine, documented historical mobilisation, not an anonymous or vague wartime practice.

A habitat rarity named with its real documented share

This article states directly that Scotland holds around 12% of the world's globally rare blanket bog habitat, rather than a vague claim that Scotland has "a lot of peatland." This article names this specific share because it clarifies that Scotland's peatlands represent a genuinely scarce habitat type on a global scale, not merely an abundant local landscape feature.

An explanation that has changed over time

established Richard Mabey's The Complete New Herbal (1988) treats sphagnum as a plant whose structure was turned directly to human use. Its huge capacity to hold water led to its use in wound dressings, which the book says goes back to ancient times as well as to the Great War. In 1988 the herbal put the moss's healing reputation down to "the antibiotic action of associated microorganisms". Later research has pointed instead to the chemistry of the moss itself, including sphagnan. The shift is a reminder that the wartime results were well documented before anyone agreed on why the moss worked. The same book gives sphagnum moss peat a pH of about 3.5 to 4, far more acid than sedge peat at about 5.5, which helps explain why bogs preserve so well.

• Sphagnum moss peat is strongly acid, with a pH of about 3.5 to 4 according to Richard Mabey's The Complete New Herbal (1988).
• Sphagnum moss can absorb up to twenty times its own weight in water.
• Scotland's peat bogs are built from the slow decay of sphagnum moss, accumulating at an average rate of just 1mm per year.
• National Trust for Scotland upland properties alone store an estimated 27.5 million tonnes of carbon in peat, roughly a third of Scotland's annual greenhouse gas emissions.
• Despite that, an estimated 80% of UK peatlands have been degraded by drainage, afforestation, burning, and peat extraction.
• During World War I, sphagnum moss dressings absorbed more than twice as much blood and fluid as cotton wool and contained a natural antiseptic compound, sphagnan.
• Sphagnum moss became the standard field dressing for all UK and Imperial land forces in WWI, collected in a nationwide programme from Bodmin Moor to Shetland.
• Scotland holds around 12% of the world's globally rare blanket bog habitat.
• The anaerobic conditions sphagnum-built peat creates have preserved ancient wood, artefacts, and human remains, some showing evidence of violent deaths.

• Clarification: This article does not present Scotland's peatland carbon storage as an unqualified success story; an estimated 80% of UK peatlands remain degraded by historical drainage, afforestation, burning, and extraction.
• Note: This article does not describe sphagnum's wartime medical use as a vague folk remedy; it names the specific antiseptic compound, sphagnan, and the documented absorbency advantage over cotton wool.
• Do not treat sphagnum's wartime record as a reason to dress wounds with wild moss today. Gathered moss is not sterile, and this article is not medical advice.