Order: Verrucariales       Family: Verrucariaceae Species: Verrucaria hochstetteri Growth type crustose. Photos: On limestone rocks. The Burren, W Ireland. BLS Burren meeting 2009 Smooth white to pale grey thallus with large sunken perithecia that leave conspicuous pits in the rock when they decay. Asci 8-spored, the spores (24-)29-34(-41) × (14-)16-20(-24) µm. Involucrellum absent. Common throughout Ireland on hard limestone and mortar. Sometimes host to the lichenicolous Opegrapha hochstetteri. Chemical reactions negative. Similar: Verrucaria baldensis. Smaller perithecia.

Verrucaria hochstetteri. BLS Burren meeting, April 2009