Arthoniaceae Arthonia punctella # Lichenicolous fungus on Diplotomma alboatrum Epithecium dark red-brown, K+ dull red or olive Occasional on thalli of Diplotomma alboatrum and D. chlorophaeum BLS conservation evaluation: LC NR Thallus absent. Spores 1-septate, 12-17 × 5-6.5(-7.5) µm, initially colourless but soon becoming warted and brown. Microscope photograph below.

Microscope photograph

Arthonia punctella
On Diplotomma alboatrum, Portland, Dorset. February 2016