A division of nonflowering plants characterized by rhizoids rather than true roots and having little or no organized vascular tissue and showing alternation of generations between gamete-bearing forms and spore-bearing forms; comprises true mosses (Bryopsida) and liverworts (Hepaticopsida) and hornworts (Anthoceropsida)
1
The Bryophyta are divided into the Hepaticae (liverworts) and Musci (mosses).
2
Others consider Pteridophyta and Bryophyta to be separate classes.
3
On the other hand we know practically nothing of Palaeozoic Bryophyta, and the evidence even for their existence at that period cannot be termed conclusive.
4
Other lines which start from the level of the primitive many-celled Algae develop into the Mosses (Bryophyta), Ferns (Pteridophyta), Horsetails (Equisetalia), and Club-mosses (Lycopodiales).