Myelochroa leucotyliza, sample from the herbarium of Prof. Göran Thor (number 40264, 2019-October-04, Nikko City, Japan, on Larix kaempferi). Many thanks to Prof. Thor for lending me this sample.
Lobes 1 – 4 mm, irregulary branched, upper surface grey-green, pustulate. Soredia and isidia absent. Lower surface black, becoming brown to the margins. Rhizines black, simple.
Cortex: K + yellow, C-, KC-, P-
Medulla: K+ weak yellow, C-, KC-, P-
atranorin, zeorin, leucotylin, secalonic acid