“Alice Algae and Freddy Fungus took a Lichen to each other and now their marriage is on the rocks because she's driving him up a tree.”
Lichens are a symbiotic relationship between a fungus and photosynthesizing algae (or sometimes cyanobacteria). Lichens are widespread and occur across all environments including extreme hot and cold. The physical appearance of the lichen is different from that of the fungus or algae alone. There are four main morphological types: Crustose – crust like and firmly attached to the substrate, Foliose – leaflike and adhere loosely to the substrate, Fruticose – have no distinct top or bottom and are often round in cross-section and are the most three dimensional and are often branched, and Squamulose – small overlapping scale-like lobes.