Thelidium sp. 2

Pykaelae, Juha, Kantelinen, Annina & Myllys, Leena, 2023, Taxonomy of Thelidium auruntii and T. incavatum complexes (lichenized Ascomycota, Verrucariales) in Finland, MycoKeys 96, pp. 1-23 : 1

Thelidium sp. 2

Description.

Prothallus not seen. Thallus whitish grey, endolithic. Perithecia 0.17-0.26 mm, 3/4-immersed, leaving deep pits; c. 40-60 perithecia /cm2. Ostiole dark, plane to depressed, c. 20-40 µm wide. Involucrellum absent. Exciple c. 0.26-0.32 mm, wall black, apex thickened.

Spores 3-septate, 30-37 x 16-18 µm.

Habitat and distribution.

The only specimen has been collected from calcareous pebbles in a lime quarry spoil in SW Lapland.

Notes.

The specimen is small. It is morphologically similar to T. incavatum and probably closely related to that species, although the relationship remains unsupported. The species may be undescribed but a better specimen is needed for type material.

Specimen examined.

Finland, Kittilän Lappi, Kolari, Äkäsjokisuu, Mannajoki, former cement factory 200 m N-NW, lime quarry spoil, on calcareous pebbles, 165 m a.s.l, 67°27'N, 23°38'E, 16 August 2018, J. Pykälä 52038 (H).