Thelocarpella gordensis gen. et sp. nov. (Ascomycetes lichenisati, Acarosporaceae)

Abstract

Thelocarpella gordensis Nav.-Ros. et Cl. Roux gen. et sp. nov., a crustose lichen with endolithic thallus, is only known from the type locality, in Provence (south-east of France), on calcareous sandstone. This species is characterized by entirely immersed perithecioid ascomata, a hamathecium consisting of a typical paraphysoid network, multispored asci (more than 1000 spores in optical section), and colourless small oblong spores. The genus Thelocarpella differs from Thelocarpon by having bitunicate asci with a distinctly thicker wall. Heterogeneity of the genus Thelocarpon and the systematic position of Thelocarpella and Thelocarpon are discussed. The genus Trimmatothelopsis Zschacke is considered a synonym of Acarospora A. Massal. and Thelocarpon robustum Eitner identical with Acarospora smaragdula var. murina (Sandst.) H. Magn.Key words: lichens, Thelocarpella, Thelocarpon, taxonomy.