Plants: Fertilization and dispersal, the first issues
Such a problem still exists for primitive plants living today such as the liverworts and mosses. Such plants practice sexual and asexual reproduction in their alternate generations. The familiar green moss is the generation which produces the sex cells. Each large egg cell remains attached to the stem at the top of the moss plant, while the smaller microscopic sperm cells are released into water and thrash their way to fertilize the egg cell. The egg cell develops while still attached to its parent plant and produces
the next asexual generation which is composed of a thin stem with, at its tip, a hollow capsule in which a large number of spores are produced. In a dry atmosphere the capsule splits releasing airborne spores. If the spores land in a suitable site they develop into new moss plants.