The bryophytes include mosses, liverworts, and hornworts. All species in this group are non-vascular meaning they have no roots. Because of this, the bryophytes are short and found in moist climates. They must absorb moisture directly through the plant itself. This is the only phylum in which the gametophyte stage is dominant to the sporophyte stage.
Bryophytes are ecologically important as ground cover in bogs.
One of the first plants to evolve, the phylum sphenopsida is made up of horsetails. The phylum lycophyta, also known as club mosses, closely resembles mosses in the phylum bryophyta but are vascular and diploid. During the Carboniferous and Devonian periods, club mosses were among the most plentiful plants on earth. Today much of our coal comes from club moss fossils. The phylum pterophyta or ferns live in a wide variety of environments and can have heights of up to 16 meters.