Mosses are small, non-vascular flowerless plants in the taxonomic division Bryophyta (, ) sensu stricto. Bryophyta (sensu lato, Schimp. 1879) may also refer to the parent group bryophytes, which comprise liverworts, mosses, and hornworts. Mosses typically form dense green clumps or mats, often in damp or shady locations. The individual plants are usually composed of simple leaves that are generally only one cell thick, attached to a stem that may be branched or unbranched and has only a limited role in conducting water and nutrients.
https://en.wikipedia.org/wiki/Moss