LICHALP

Verrucaria rivalis Zschacke

Lichenised. Poorly known taxon.

Substrate:

Altitudinal range: from the montane belt (potential vegetation: deciduous forests dominated by Fagus sylvatica and closed coniferous forests with Picea abies) to the subalpine belt (potential vegetation: open, taiga-like forests dominated by Larix decidua and/or Pinus cembra and Rhododendron)

Note: a species close to V. submersella, with a very thin, continuous, grey thallus, semi-immersed ascomata (to c. 0.5 mm in diam.), a carbonised involucrellum adpressed to the protruding part of the perithecia and fusing with the perithecial wall, and ellipsoid ascospores (to c. 30 µm long); on calcareous stones in montane to subalpine streams, reported from a few scattered localities in the Alps.