A tendency of the
evolution in plants has towards the
formation of that are
independent from . In bryophytes
and in the fecundation is
totally on water. In
phanerogamic such dependency
does not .

Another tendency is the in the
size and of the gametophyte.
In the gametophyte is
indeed lasting stage. In
pteridophytes, and
angiosperms it became temporary
stage and its size was
successively reduced.

third evolutionary trend relates the
inter-dependency between gametophytes
sporophytes. In bryophytes the
is entirely dependent on
gametophyte to survive. In
remaining plants the sporophyte the
independent stage and once
autotrophic gametophyte in
and pteridophytes became dependent
the sporophyte in the
plants.