There is controversy, but until it is resolved: traditionally
the bryophytes are divided into 3 main groups:
Marchantiophyta (liverworts),
Bryophyta (mosses),
Anthocerotophyta (hornworts).
Bryophytes are one of the two main groups of plants. Their
distinguishing feature is that they are non-vascular plants. All
other plants are vascular. They are spore-producing plants (but not
all spore producers are byophytes), and none have flowers.