Nomenclatural notes on the lichen genera Leucodecton and Myriotrema (Graphidaceae) in India

Nine species of Leucodecton and nine species of Myriotrema are recorded for India. The recently resurrected Leucodecton accommodates species earlier placed in Leptotrema, Myriotrema, or Thelotrema, which were segregated based primarily on medullary chemistry such as stictic and norstictic acids, although Myriotrema retains species with a prosoplectenchymatous cortex and psoromic or protocetraric acid chemosyndromes. This contribution includes new synonyms, changes in generic placement, new species distributions, and new records. Leucodecton compunctum and L. subcompunctum are new records for India.