Order: Acarosporales       Family: Acarosporaceae Species: Acarospora impressula Growth type crustose. Photos: On granite boulder at Black Head, The Burren, W Ireland. BLS Burren meeting 2009 Small patches or streaks of red-brown thallus with small, angular areoles less than 2mm wide. Dark-brown to blackish apothecia. Scarce, mainly coastal on siliceous rocks, especially granite. Chemical reactions negative. Similar: A. fuscata K-, C+ red, KC+ red

Acarospora impressula. BLS Burren meeting April 2009 and immediately above Co.Cork June 2009