Species: Dermatocarpon meiophyllizum
Photos: On rock in stream. Ballingeary, Cork, SW Ireland.
Specimen identified by Mike Simms
Light to dark brown or greyish-brown thallus, 8-18mm diam, pruina absent or thin. Lower surface dark or black-brown, attached by central holdfast. Lobes usually smooth, rarely folded or wrinkled. Intermediate in size between D. luridum and D. leptophyllodes.
Found on intermittently-submerged siliceous rocks by streams, rivers and lakes. Chemical reactions negative.
Above: Dermatocarpon meiophyllizum with Dermatocarpon luridum. May 2009