Buellia hyperbolica  

Thallus of white, pale grey to yellow-green granules, ± continuous, usually covering a wide area.
Anamorph: not known.
Teleomorph: ascomata apothecia, 0.2-0.3 (-0.4) mm diam., adnate, abundant and confluent; disc plane at first, often becoming ± hemispherical. Proper margin very thin, and even when juvenile becoming almost totally excluded. Exciple poorly developed, to 20 μm thick. Hymenium without oil droplets, 70-90(-100) μm high. Hypothecium with abundant oil droplets, 100-120 μm tall. Interascal tissue of paraphyses with the apical cells markedly swollen and (3.5-) 4-5 μm diam., pigmented dark brown. Ascospores (19-) 21-24 (-29) × (7.5-) 8-9.5 (-11) μm, when young with inner wall thickened at septum; when mature walls uniformly thin; apices pointed, often slightly curved, finely ornamented.
Chemistry: thallus C–, K+ yellow-brown, Pd+ orange-red, UV– (± atranorin, fumarprotocetraric, protocetraric, confumarprotocetraric and ± convirensic acids).