The lichens are unique group of organisms with symbiotic association between a fungus and an alga or cyanobacteria. The lichens are defined as “a self-sustaining ecosystem formed by the interaction of an exhabitant fungus and an extracellular arrangement of one or more photosynthetic partners and an indeterminate number of other microscopic organisms” (Hawksworth and Grube 2020). In the world till date about 20,000 species of lichens are known to occur. The tropical rain forests have the highest species richness and 600 or more species can be found just within a km2 (Lücking et al. 2009). India has rich diversity of lichens represented by 2985 species, 6 subspecies, 35 varieties and 2 forma, distributed under 469 genera and 88 families. Among different states of India Uttarakhand represent maximum number of lichens with 998 taxa followed by Tamil Nadu and West Bengal wit...