Verrucaria samosensis Servit , Stud. Bot. Cech . 9: 105, 1948

Pykaelae, Juha, Kantelinen, Annina & Myllys, Leena, 2020, Taxonomy of Verrucaria species characterised by large spores, perithecia leaving pits in the rock and a pale thin thallus in Finland, MycoKeys 72, pp. 43-92 : 43

Verrucaria samosensis Servit, Stud. Bot. Cech. 9: 105, 1948

Type.

[Greece,] Samos, Vathy, Rechinger (PRM-858434!, holotype).

Description.

Prothallus not seen. Thallus whitish-grey, endolithic to thinly epilithic, occasionally irregularly rimose around perithecia. Perithecia 0.22-0.28 mm, (1/2-)3/4-immersed, leaving shallow to deep pits in the rock; ca. 70-80 perithecia/cm2. Involucrellum enveloping the exciple, 40-50 mm thick. Exciple 0.19-0.28 mm in diam., wall black. Periphysoids ca. 50-60 × 2-2.5 mm. Ascospores 0-septate, ca. 21-25 × 11-13 mm.

Notes.

According to the protologue, the spores may be larger: 20-29 × 9-15 mm ( Servít 1948). The species differs from V. bifurcata by longer periphysoids and possibly by slightly shorter, but broader spores.