LICHALP

Thelidium parvulum Arnold

Lichenised. Poorly known taxon.

Substrate: calciferous rocks

Altitudinal distribution: montane belt (potential vegetation: deciduous forests dominated by Fagus sylvatica and closed coniferous forests with Picea abies)

Note: a species with a thin, greenish thallus, protruding, black, hemispherical perithecia lacking an involucrellum, and 1- to 3-septate ascospores (to c. 25 µm long); on sandstone and limestone at low elevations; widespread in extra-Alpine Central Europe, with a single record from the Eastern Alps (Austria).