Teloschistaceae Caloplaca asserigena Growth type crustose Chemical results: Thallus K-, hymenium slightly K+ purplish Very local distribution on twigs of Salix and Calluna BLS conservation evaluation: LC NS Very small patches of greyish thallus with tiny, crowded apothecia, discs rusty-red becoming much darker with age. Spores 9-12 x 5-6.5 µm, the septum a third to a quarter the length of spore. Microscope photograph below.

Microscope photograph

Caloplaca asserigena
On Calluna stem. Studland, Dorset. September 2012