Sphagnum moss is a type of moss that is used primarily as an amendment for soil. Sphagnum plants are bog plants that, when harvested and dehydrated, are sold for use in landscaping or home gardening. This moss is a highly desirable type of organic matter, according to Texas A&M University's website.
Sphagnum moss is native to the northeastern part of the United States and Canada. This plant has also been found growing in Alaska, Wisconsin and Minnesota, according to the U.S. Department of Agriculture Forest Service. Sphagnum moss thrives in wet, boggy areas that contain acidic soil.
Sphagnum moss is a clumping, spreading perennial with short roots. The plant often floats on the surface of water, creating a mat so dense that it has been known to support the weight of large animals--even moose, according to Brandeis University.
Sphagnum moss has very tiny, slender leaves that grow straight out from the stem. The stems rarely grow over 4 inches tall. The leaves can be light green, burgundy, brown, yellow or pink in color, depending on the species, but most are green.
Sphagnum moss is known for its ability to absorb water, according to Texas A&M University. The plant has large amounts of water-storing cells. A clump of live sphagnum moss can soak up large amounts of water--up to 20 times its weight in water. Then, the moss can be wrung out and used again to soak up water.
Sphagnum moss is high in acidity. This fact makes the moss able to inhibit bacteria growth. For that reason, it was often used to treat wounds during World War I, according to the Moutere River Company's website. Today, dried sphagnum moss is harvested and used to improve soil. When added to heavy soil, it helps the soil drain better and loosens it up. If added to light soil, it aids in nutrient and moisture retention.