Order: Lecanorales Family: Porpidiaceae
Species: Porpidia hydrophila
Photos: On siliceous rock. Co. Cork and Co. Kerry, SW Ireland
Smooth, finely cracked pale grey or bluish-grey thallus, often tinged orange or greenish with inconspicuous or dark prothallus. Large scattered black apothecia, convex when mature, occasionally pruinose. Abundant black pycnidia. Asci 8-spored with colouless simple spores, 18-23 x 7-9 Ám. Microscope photographs below.
Found on siliceous rocks in and beside upland loughs and streams and on flushed moorland rocks.
Chemical reactions negative. Epithecium greenish-blue in section.
Similar: Porpidia cinereoatra, epithecium brownish-green.