Myriotrema thailandicum

Myriotrema thailandicum is a species of lichen in the family Graphidaceae. Found in Thailand, it was formally described as a new species in 2002 by lichenologists Natsurang Homchantara and Brian J. Coppins. The type specimen was collected from Namtok Phlio National Park (Chanthaburi Province) at an elevation of 100 m. Here, on a trail close to the Phlio waterfall, it was found in a lowland rainforest, growing on both rocks and tree trunks. The lichen has a smooth and shiny, greenish-grey thallus with a dense cortex and a white medulla. It contains fumarprotocetraric acid, and sometimes has trace amounts of protocetraric acid.