Lichen (Arthonia radiate) fungal spores, light microscopy. Lichens are symbiotic organisms formed of a fungus and an alga that mutually benefit one another. The alga is contained within the hyphae (filaments) of the fungus. Many Lichen reproduce asexually, and the spores are made up of algal cells surrounded by fungal filaments. They are therefore protected from harsh conditions, and in particular from desiccation. The alga supplies the fungus with nutrients that it makes by photosynthesis.