Gymnoderma coccocarpum Gymnoderma coccocarpum Nyl. Gymnoderma coccocarpum is a small foliose lichen growing together with mosses on trunks of Cryptomeria japonica. It has primary squamules up to 40 mm long, 2-8 mm wide, up to 0.2 mm thick, with no cortex on the lower surface. The apothecia has short podetia and grows on the margin of squamules and the thickness of the cortex is less than twice that of the medulla. It contains didymic acid and atranorin as chemical substances. The thallus UV + blue white. The species is known to grow in Himalayas in China and in Japan. In Japan, it is found in the natural forest of Cryptomeria japonica, about 800 m above sea level in Yakushima. distribution map of Gymnoderma coccocarpum