Biatora veteranorum
Thallus effuse, thin, pale, indistinct.
Anamorph: conidiomata pycnidia, 0.08-0.12 mm diam., 0.08-0.15 mm high, sessile to short-stalked, white-pruinose. Conidiophores unbranched. Conidia 2.8-3.5(-3.8) × 0·8-1(-1.2) μm, simple, bacilliform, hyaline.
Teleomorph: ascomata apothecia, 0.16-0.4 mm diam., discoid, white, becoming pale brown. True exciple poorly developed. Epithecium pale orange with minute crystals dissolving in K. Hymenium ca 30 μm high, colourless. Proper margin distinctive with conglutinate radiating hyphae. Interascal tissue of paraphyses, simple, rarely branched, 1-1.5(1.7) μm diam, widening above to 2.8 μm diam. Asci clavate, Biatora-type. Ascospores (6.5-)8-10(-11.5) × 2.3-3 μm, ellipsoidal, 1-septate.
Assessed as Vulnerable (D1) by Woods & Coppins (2012). The species may be overlooked (or unrecognized as a lichen). Most of the surveys of known sites to date have only found the species on single trees - suggesting that it is genuinely restricted in distribution.
Threats include shading caused by vegetation growing up around the ancient trees that harbour this species, fire in dry periods, and also continued supply of suitable habitat in the form of substantially sized dead timber.
Biatora ligni-mollis is similar but lacks pycnidia and the ascomatal discs are not pruinose. That species has only been reported from a single locality in the Scottish Highlands.
England (Bedfordshire, Derbyshire, Shropshire), Scotland (Angus, E Inverness, E Lothian, Midlothian, Moray).
In GB&I, on lignum or dry bark of ancient trees (mostly Quercus, also Pinus and Salix).