Hemithecium hainanense sp. nov. and a checklist and key to Hemithecium species from China

Hemithecium hainanense from Hainan Island, China, is described as new to science. The lichen is characterized by erumpent lirellae with a lateral to complete thalline margin, large transparent transversely septate ascospores, and the presence of norstictic acid. Hemithecium chlorocarpum is reported as a new record from China. A checklist and key to Hemithecium species from China are presented.