Order: Arthoniales Family: Roccellaceae
Species: Schismatomma umbrinum
Photos: On rock. Killarney NP, Co. Kerry, SW Ireland.
Identified by John Douglass
Thick, yellowish-brown thallus surrounded by a wide purplish-brown prothallus, mosaic-forming or in rosettes. Central parts of thallus become concolorously sorediate. Apothecia are rare, discs blackish-brown. Chemical reactions negative, medulla and abraded soralia UV+ ice-blue.
Found on vertical sides and underhangs of sheltered siliceous rocks in old, humid woodlands. Rare, Irish records only from Co. Kerry.
Schismatomma umbrinum. November 2010