The Fascinating Use of Moss

Leenie Wilcox
Jan 28, 2023
3 min read

Cotton is well known for its soft, durable, and absorptive nature, but it might not be so clear why the moss has seen plenty of use historically. Indigenous people used moss as an absorptive and sanitary material for diapers and menstruation products, and dried moss was frequently used in cradles as a dual purpose pillow [3, p 106-107].

Mosses are poikilohydric plants, that is, they are organisms whose water content mirrors the moisture in the surrounding environment [3, p 36]. Accordingly, mosses are unique among plants in their biological ability to capitalize on sporadic access to water. Sphagnum moss, for example, has the ability to absorb between twenty and forty times its dry weight in water [3, p 107].

Moss leaves, unlike tree leaves, have no wax coating and are only one cell thick [3, p 39]. This aids in water absorption since every cell of the leaf is accessible to water. Due to its size, to remain hydrated moss needs to harness the power of the water molecule. Moss cell walls possess both positive and negative charges, making them particularly attractive surfaces for water molecule adhesion [3, p 39]. This hydrophilic property is due to the molecular structure of water, in which the oxygen atom possesses a mildly negative charge and the hydrogen atoms mildly positive charges [4]. Since moss and water share a similar bipolar nature, either end of the water molecule may come in contact with the cell wall and yet experience an attractive electric force [3, p 39].

In World War I, wound infections were common and often the result of uniform scraps contaminating the injury [1, p 29]. Soldiers’ uniforms were often saturated in mud, bacteria, and sewage from the trenches and battlefields, and a bullet that pierced skin had to first pass through the polluted uniform [1, p 29]. This introduced foreign bacteria and toxins deep into the body, and greatly increased the likelihood of infection [1, p 29]. In their research (1914), professor Isaac Bayley Balfour and surgeon Charles Walker Cathcart provided proof that moss was capable of absorbing bodily fluids including pus and blood [1, p 29]. Bodily fluids were absorbed by the plant in the same manner and with the same effectiveness as water [1, p 29].

Additionally, sphagnum moss is capable of altering the pH of its surrounding environment due to high concentrations of uronic acids within the plant’s cell walls [1, p 30]. When in an environment with a pH greater than two, the uronic acids ionize, allowing the moss to collect cations and lower the surrounding environment’s pH [1, p 30]. Sphagnum moss’ ability to acidify its environment endows the plant with antiseptic properties [1, p 30]. Pathogenic bacteria thrive in environments whose pH is approximately that of human blood, or 7.4 [1, p 30]. Acidification of the environment impedes bacterial growth and aids in the recovery of an infection [1, p 30].

In response to these findings, the British War Office commissioned the harvesting, processing, and conversion of sphagnum moss into millions of wound dressings during the War [1, p 27-28]. Used extensively by the Germans and Allies alike, sphagnum was a favorite material for surgical dressings [1, p 28].

I wouldn't mind giving moss a place in my wardrobe...