Thelocarpon coccosporum
Anamorph: not known.
Teleomorph: ascomata perithecial, 120-200 µm diam, globose, scattered, slightly immersed, the ostiolar region yellow-pruinose, apparently without a thallus. Ascomatal wall ca 30 µm thick above, 20 µm below, colourless. Ostiole with periphyses ca 12 µm in length, shorter at the sides, slightly branched. Interascal tissue absent. Hypothecium I+ pale blue. Asci 70-120 x 12-20, flask-shaped, persistent, not blueing in iodine, enveloped in very viscous hymenial gel that is I+ yellow then yellow-red, KI+ blue, multispored. Ascospores 3.5-5 (-6) µm diam, spherical, aseptate, hyaline, without an epispore, gelatinous sheath or appendages.
Assessed by Woods & Coppins (2012) as of Least Concern, but listed as Nationally Rare due to the small number of records.
Recognized by its yellow pruinose perithecia that lack an outer thalline layer and paraphyses, the asci enveloped in a distinct viscid gel, and the globose ascospores.
Not obviously lichenized, but algae are present under and around the base of the ascomata.
In GB&I, known from England (S Northumberland) and several sites in southern Scotland, reported elsewhere from Austria, Germany and Luxemburg.
In GB&I, reported from sandstone headstones in churchyards. BLS map not yet prepared.