All plants need to reproduce in order to expand their species, but non-vascular plants do not produce flowers or seeds. Non-vascular plants can reproduce sexually and asexually, though asexual reproduction is not a very common method.
During asexual reproduction, plant material gets regenerated when any part of the plant such as leaves fall to the ground. This results in growth of secondary plants.
During sexual reproduction, the archegonia, present on female gametophytes on the top leaves of mosses, produce egg cells. The sperm cells are produced by Antheridia, present on the male gametophytes. The sperm cells require water such as a dew or rain drop to reach archegonium where they fertilize the egg cells. The resulting zygote develops into a sporophyte that is inside the archegonium. Gradually, it takes the shape of a slender stalk with a spore capsule on its tip. In this capsule, haploid spores are produced by the process of meiosis. This capsule opens up to free up the spores. These spores get buried in soil and produce gametophytes.