Porpidia crustulata Porpidiaceae
Porpidia crustulata

Growth type crustose
Chemical results: Medulla usually K+ yellow, C-, P+ orange
Identification: Bryan Edwards

Common on siliceous rocks, stones and pebbles, occasional on wood. Most frequent in lowland and urban areas.

Very thin cream or pale-grey thallus sometimes only visible as dark stain (but can be reddish near water), the abundant black, convex apothecia (approx 1mm diam) usually in lines or groups.
Porpidia soredizodes is the fertile counterpart

Similar: Porpidea macrocarpa. Apothecia to 3mm diam

Porpidia crustulata

Porpidia crustulata
Porpidia crustulata
On pebble. Holton Lee, Dorset. March 2013

All images used are copyright. Please contact me if you find errors.