LICHALP

Thelidium subabsconditum Eitner

Syn.: incl. Thelidium circumvallatum Zschacke

Lichenised.

Substrate: calciferous rocks

Altitudinal range: from the montane belt (potential vegetation: deciduous forests dominated by Fagus sylvatica and closed coniferous forests with Picea abies) to the alpine belt (potential vegetation: treeless Alpine grasslands and tundras, to the lower limit of perennial snow and the equilibrium line of glaciers)

Note: a species resembling Th. absconditum in the entirely immersed perithecia (to c. 0.2 mm in diam.) lacking an involucrellum, but with a very thin, bluish grey thallus, and smaller, 1-septate ascospores (less than 25 µm long); in the Alps it is common on inclined surfaces of compact calciferous rocks in rather shaded, non-eutrophicated situations, but it was not always distinguished, and the distribution appears incomplete.