Sphagnum’s acidity made it the main wound dressing in World War I

Evidence

Sphagnum is thorough in its manipulation of its environment. Not only does it produce waterlogged, nutrient-poor conditions; it also changes the pH, just for good measure. Sphagnum acidifies the water in which it grows, making it inhospitable for other plants. Release of acids allows Sphagnum to absorb scarce nutrients for its own use. The water at the edge of a bog may have a pH of 4.3, equivalent to dilute vinegar. The acidity contributes to the antimicrobial properties of the moss. Most bacteria are inhibited by low pH. Because of this and its unsurpassed absorptive abilities, Sphagnum was once widely used as bandages. In World War I, when cotton supplies were limited by warfare in Egypt, sterile Sphagnum became the most widely used wound dressing in military hospitals. — Robin Wall Kimmerer, Gathering Moss, 460

Categorization

• XREF: connects to: Waterlogged bog peat preserves organic material largely unchanged for centuries — Robin Wall Kimmerer, Gathering Moss: A Natural and Cultural…, 456; Only one in twenty cells in a Sphagnum plant is actually alive — Robin Wall Kimmerer, Gathering Moss: A Natural and Cultural…, 452