• Verrucaria calciseda DC.
Verrucaria calciseda
Click on map to open large map in new window
(Map updated: 11 August 2009)

This species of calcareous rocks has its whitish thallus immersed in the rock. The discs (perithecia) are in pits and have tiny, hairline cracks radiating from some of them like a child’s drawing of the sun. The spores often have dark contents which can be a good identification character. In Ireland, the species is local but not rare (Counties Clare and Sligo).

Key characteristics

  • Thallus white with perithecia in pits and with small cracks radiating away from some of these
  • Spores about 25µm long and spore sacs (asci) often with cloudy or darkened contents.

Original text submitted by Vince J. Giavarini

 Simms, M. J., (2016). Verrucaria calciseda DC.. [In] LichenIreland. Accessed on 2019-08-25.