This moss is easy to recognize by its bright yellow-green color. Found in acidic, moist habitats, ribbed bog moss consists of unbranched (or rarely branched) stems in clumps. The stems are covered in dense red-brown rhizoids, looking like a layer of felt (may need to scrape away leaves to see this). Shoots are 3-10 cm long. The leaves are acutely-tipped, distinguishing it from A. turgidum.
Glow moss is dioecious. Plants are not typically fertile in Denali, and spread vegetatively instead. Plants sometimes produce specialized leaves in a terminal cluster, which are designed to break off and spread the plant asexually.