lf on Phaeographis dendritica?

[peterbisset]

Came across what looks like an lf on Phaeographis dendritica (black under the lirellae), the spores of the lf were not abundant but look like an Arthonia, but are too big around 22.5 mu and 5-6 septate. My other thought is that it is a bark fungus erupting through the lichen. Linchmere common SU864315 VC13 West Sussex

[Neil Sanderson]

I think that is a bark fungus, it looks like it occurs off the thallus, but there is an undescribed Arthonia found on Phaeographis dendritica and Phaeographis smithii, which is very similar to Arthonia graphidicola, that I have collected from The Dizzard and the nearby Millook woods on the north Cornish coast.

A description from my herbarium:

Irregularly rounded to sub-stellate dark brown apothecia; parasitic on Phaeographis smithii; epithecium brown K+ pale green; hymenium 50µm tall, pale brown, K+ pale green; patchy hyothecium, brown K+ green; spores 2 – 3 septate, with large end cells, 15 x 5µm. Spores

If anyone finds it elsewhere I would welcome collections!

Neil