Arthonia graphidicola Arthoniaceae
Arthonia graphidicola #

Chemical results: Epithecium K+ dull olive

Lichenicolous on thallus of Graphis scripta. Frequent in W Scotland, scattered records from elsewhere in Britain and Ireland.
BLS conservation evaluation: LC NS Sc IR

Thallus absent, scattered red to dark brown, rounded, elongate or fleck-like apothecia developing below the bark and then erupting through host thallus. Spores 2-3 septate, upper cells enlarged, (13-)14-17 4.5-5.5 m. Initially smooth and colourless, becoming brown warted. Micro photo below.

Similar: Stigmidium microspilum (black perithecia) also found on G. scripta. Arthonia thelotrematis occurs on Thelotrema lepadinum

Arthonia graphidicola

Arthonia graphidicola

Microscope photograph
Arthonia graphidicola
Arthonia graphidicola
On Graphis scripta. Studland Heath, Dorset. May 2015

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