Gelatinous lichens are lichens in which the phycobiont (The principal symbiont ) is a cyanobacterium.
Cyanobacteria is a large and varied group of bacteria which possess chlorophyll and which carry out photosynthesis. Having cyanobacteria as their photosynthetic partners they produce a polysaccharide that absorbs and retains water. They become gelatinous when wet and brittle when dry.
