Polytrichum moss is a medium-sized moss notable for its upright, spiky appearance, often forming dense, green to dark green carpets in moist, acidic environments. Its leaves are lance-shaped with toothed margins, arranged in a spiral around its stiff, reddish stems. The capsule, held aloft on a long seta, is cylindrical, assisting in spore dissemination. It thrives in cool temperate areas, with a remarkable ability to withstand and recover from desiccation.