Verrucaria grossa Nyl., in Nylander & Saelan, Herb. Mus. Fennici 111, 1859

Type.

[Russia,] Lapponia Rossica, 1843, F. Nylander (H!, holotype or syntype).

Description.

Prothallus not seen. Thallus grey, rimose. Perithecia ca. 0.4-0.6 mm, 1/2-immersed, leaving deep pits in the rock. Involucrellum enveloping the exciple, ca. 50-100 mm thick, thicker at apex. Exciple ca. 0.3-0.4 mm in diam., wall black. Ascospores in very poor condition, 0-septate, ca. 22-25 × 10 mm.

Notes.

The specimen in H is small and in a very poor condition. Vainio (1921) reported the spore size of 15-24 × 10-18 mm. Pykälä (2010b) reported the species new to Finland. The Finnish specimen (the sequencing failed) may be rather similar to the one sectioned perithecium of the type of V. grossa, which, however, had spores in poor condition. Verrucaria grossa should be treated as a species with unresolved identity unless better type material can be located.