They have no vascular tissue or wood, nor do they have large leaves or showy cones or flowers. This does not mean that mosses are not important. Mosses play important roles in reducing erosion along streams, water and nutrient cycling in tropical forests, and insulating the arctic permafrost. Mosses have structures that anchor them and absorb water as well as structures that catch sunlight for photosynthesis, but they have no true roots or leaves. The sphagnum moss is known for its moisture holding capacity, absorbing up to 20 times its dry weight with water.
Mosses produce sexually by forming spores.
Sperm from one gametophyte fertilizes the egg of another, producting a zygote. A stalk-like structure, called a Sporophyte, with a capsule at the top containing the spores grows from the zygote. When released, the spores will grow into new gametophytes. All mosses show alteration of generations. Ferns are vascular plants forming true roots, stems, and leaves.