Description: This common aquatic species with a pale green-grey, almost white-grey when dry, cracked thallus (smoother when young), has its immersed discs (perithecia) barely projecting above the surface; the tip of the disc is only visible as a pink or brown dot. Spores two to three times longer than wide; main range 18–25µm long. It occurs on acid and calcareous rocks of both river and lake margins. It is tolerant of shade; throughout Ireland. Care needs to be taken not to confuse with some forms of V. aethiobola (for example, V. csernaensis).

Key Identification Features:

• Aquatic lichen; thallus pale green, cracked with immersed discs, the tops just visible
• Spores simple, two to three times longer than wide.

Original text submitted by Vince J. Giavarini

Distribution Map from NBN: Verrucaria praetermissa at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Verrucaria praetermissa at iNaturalist World Species Observations database.