Irish lichens

Porpidia crustulata
Order: Lecanorales       Family: Porpidiaceae

Species: Porpidia crustulata

Growth type crustose.
Photos: Gougane Barra, Cork, SW Ireland.
Identified by John Douglass

Very thin cream or pale-grey thallus that is sometimes only visible as a dark stain and can be reddish near water. The abundant black, convex apothecia (approx 1mm diam) are usually in lines or groups. Asci 8-spored. Spores colourless, simple, 10-16 x 6-9 Ám.
Porpidia soredizodes is probably the sorediate counterpart.
Medulla usually K+ yellow, C-, P+ orange

Common on siliceous rocks, stones, pebbles and upland scree.

Similar: Porpidia cinereoatra

Porpidia crustulata

Porpidia crustulata

Immediately above: Porpidia crustulata, the Burren, April 2009

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