Moss (seed plants and pteridophytes), where the diploid sporophyte generation is dominant. Mosses are now classified on their own as the division Bryophyta. There are approximately 12,000 species. The main commercial significance of mosses is as the main constituent of peat (mostly the genus "Sphagnum"), 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. Botanically, mosses are non-vascular plants in the land plant division Bryophyta. They are small (a few centimeters tall) herbaceous
Moss Antarctica and Russia, and a case is put forwards for Carboniferous mosses. It has further been claimed that tube-like fossils from the Silurian are the macerated remains of moss calyptræ. Mosses also appear to evolve 2–3 times slower than ferns, gymnosperms and angiosperms. Recent research show that ancient moss could explain why the Ordovician ice ages occurred. When the ancestors of today's moss started to spread on land 470 million years ago, they absorbed CO from the atmosphere and extracted minerals by secreting organic acids that dissolved the rocks they were growing on. These chemically altered rocks in turn reacted