Taxonomy of Verrucaria species characterised by large spores, perithecia leaving pits in the rock and a pale thin thallus in Finland Author Pykaelae, Juha Biodiversity Centre, Finnish Environment Institute, Latokartanonkaari 11, 00790 Helsinki, Finland https://orcid.org/0000-0002-7566-9310 juha.pykala@ymparisto.fi Author Kantelinen, Annina Botanical Museum, Finnish Museum of Natural History, P. O. Box 7, FI- 00014 University of Helsinki, Finland Author Myllys, Leena Botanical Museum, Finnish Museum of Natural History, P. O. Box 7, FI- 00014 University of Helsinki, Finland https://orcid.org/0000-0002-9566-9473 text MycoKeys 2020 72 43 92 http://dx.doi.org/10.3897/mycokeys.72.56223 journal article http://dx.doi.org/10.3897/mycokeys.72.56223 1314-4049-72-43 5243D130A7EF55F3856E1E3722F204D5 Verrucaria pustulifera Servit , Stud. Bot. Cech . 11(3): 120, 1950 Type. Slovakia, in valle fl. Hnilec, pr. R. Ztratena , 800 m alt., calc., 1933, Suza (PRM 858074!, syntype). Description. Prothallus not seen. Thallus grey, endolithic to semi-endolithic. Perithecia 0.25-0.33 mm, 3/4-immersed, leaving deep pits in the rock, usually surrounded by a thalline collar or is covered by a thin thalline layer except for the apex. Ostiole pale, plane, ca. 20-50 mm wide. Involucrellum covering half of the exciple, ca. 50-70 mm thick, diverging from the exciple. Exciple ca. 0.3-0.33 mm in diam., wall pale brown. Periphysoids ca. 25-30 x 2-2.5 mm. Ascospores 0-septate, 27-38 x 12-15 mm. Notes. Verrucaria pustulifera differs from V. subjunctiva in a pale brown exciple and shorter periphysoids. The involucrellum is also smaller than usually in V. subjunctiva . Verrucaria kuusamoensis has smaller spores.