Moss. View of moss (green) and lichen (blue/green) growing on the trunk of a birch tree. Moss is found in wet habitats. Mosses produce spores which germinate into gametophytes, the green part of the moss. Male and female sex organs develop on the gametophyte, and produce sperm and eggs. The male sperm migrate to the female cells through a film of water on the plant's surface. Damp conditions are also needed because mosses have no true roots and depend on their leaves to absorb water and minerals. Lichen is a fungus growing in symbiotic association with an alga. Photographed in Northumberland National Park, England.