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. Dawsonia, the tallest moss in the world, can grow to 50Â cm in height. Lichens may superficially look like mosses, and have common names that include the word "moss" , but are not related to mosses.:3 Mosses used to be grouped together with the hornworts and liverworts as "non-vascular" plants in the former division "bryophytes", all of them having the haploid gametophyte generation as the dominant phase of the life cycle. This contrasts with the pattern in all vascular plants , where the diploid sporophyte generation is dominant. The main commercial significance of mosses is as the main constituent of peat , although they are also used for decorative purposes, such as in gardens and in the florist trade. Traditional uses of mosses included as insulation and for the ability to absorb liquids up to 20 times their weight. They are small herbaceous plants that absorb water and nutrients mainly through their leaves and harvest carbon dioxide and sunlight to create food by photosynthesis. As in liverworts and hornworts, the haploid gametophyte generation is the dominant phase of the life cycle. The spore-bearing sporophytes are short-lived and dependent on the gametophyte for water supply and nutrition. Also, in most mosses, the spore-bearing capsule enlarges and matures after its stalk elongates, while in liverworts the capsule enlarges and matures before its stalk elongates.
