Herpothallon polyisidiatum

Herpothallon polyisidiatum is a species of corticolous (bark-dwelling), crustose lichen in the family Arthoniaceae. Found in China, it was formally described as a new species in 2022 by Pengfei Chen and Lulu Zhang. The type was collected from Mangshan National Forest Park (Qingyuan, Guangdong) at an elevation of 1716 m. The lichen contains stictic acid, a lichen product that can be detected using thin-layer chromatography. The species epithet refers to polyisidiatum refers to the pseudisidia, which are plentiful in this species.