New Distributional Records of the Genus Usnea (Lichenized Ascomycota) from Arunachal Pradesh, India

The genus Usnea Dill.ex Adans. is worked out based on the new collections and represented by 29 species in the state of Arunachal Pradesh, a biodiversity hotspot in north-east India. Six species viz. Usnea angulata Ach., U. compressa Taylor, U. himalayana Bab. U. montisfuji Motyka, U. perplexans Stirt., U. picta (J. Steiner) Motyka are new additions to the state lichen biota. Two species namely U. cineraria Motyka and U. thomsonii Stirt. are endemic to the Himalayan region. The genus is a potent source of phytomedicine and has multifarious ethnobotanical, phytochemical and pharmacological significance. An identification key to all the species is provided to facilitate their identification while new additions to the state are dealt briefly along with their photographs and a table showing the distribution of species within the state. Indian species of Usnea need thorough phytochemical screening to record their unique uses for the human benefits.