The diploid sporophyte consists of a sporangium-bearing stalk that grows directly out of the gametophyte. Spore mother cells within the sporangium undergo meiosis, producing numerous haploid spores that fall to the ground like tiny particles of dust. Consequently, the sporophyte of the moss is heterotrophic and parasitic on the gametophyte. Most moss gametophytes are dioecious, with separate male and female individuals in the population. Mosses have a primitive method of fertilization that involves a motile, biflagellate sperm that swims through water to reach the egg on female plants.
Lichens are essentially fungi containing symbiotic algal cells.
The photosynthetic algae provide carbohydrate nutrition for the fungus, while the fungus provides a protective place for the algal cells to thrive in an otherwise hostile environment. Nature's Perfect Marriage Fern Life Cycle Fern Life Cycle . In tree ferns, the leaves are produced on a definite woody trunk. On the underside of the leaves are rows of brown sori. Each sorus is composed of a cluster of sporangia, and is often covered by a thin outer layer called the indusium.