A new species of Thelocarpon from Dutch quarries, with a worldwide key to the species of the genus

Thelocarpon periphysatum sp. nov. is described from marl quarries in the Netherlands. The species is characterized by perithecioid ascomata that have a green-yellowish ring around the ostiole, abundant periphyses and periphysoids that are up to 120 mu m long, the absence of paraphyses and the wide, oblong and often somewhat asymmetrical ascospores. The perithecia are immersed in black cyanobacterial crusts on calcareous rocks. A worldwide key is provided to the 30 species of Thelocarpon that are currently accepted.

Automated summary

The new species Thelocarpon periphysatum is described from marl quarries in the Netherlands. It is characterized by perithecioid ascomata with a green-yellowish ring, abundant periphyses and periphysoids up to 120 μm long, absence of paraphyses, and wide, oblong, and often asymmetrical ascospores. The perithecia are immersed in black cyanobacterial crusts on calcareous rocks. A worldwide key to the 30 currently accepted species of Thelocarpon is provided.