Mosses are among the simplest plants and though they come in many shapes and sizes, they share the same reproductive process. They do not produce flowers. Instead, they go through a reproductive cycle with two growth stages. The first produces the plant itself. As it grows, portions will differentiate into male and female parts. When fertilization occurs, the next growth stage begins and the plant will produce spores that will begin the reproductive process again.
Moss life cycles begin with a spore dispersed by the wind. Spores that land in fertile conditions will germinate and produce thin thread-like growths called protonema, which are the juvenile form of the plant.
As the protonema continues to grow, it will eventually produce buds above ground and rhizoids, tiny root-like structures below. The rhizoids will anchor the plant and provide nutrients from the soil.
The buds will eventually form leafy growths. Some of these will become gametophytes, the reproductive parts of the moss. Some will mature into the male parts of the plant, called antheridia, while others will form the female parts called archegonia.
The antheridia will produce flagellate sperm that will be splashed to the archegonia by rain water. The sperm will then swim to and fertilize the egg. This then forms a zygote.
The zygote will then grow into a sporophyte. This is a stem-like projection that grows from the gametophyte. At the tip of the sporophyte is a capsule, which contains new spores. When the capsule ripens, it will open to release the spores, starting the life cycle over.