TYPE. UNITED KINGDOM. ENGLAND, “Leight. Lich. Brit. Exsic. 224. On oaks: “Newton Wood, Stagdale, and Oggeray Hillm Cleveland, Yorkshire” as cited in Leighton (1856). Possible type specimens include O 204726 and S F133344.
Description. Lichenized fungus.
Thallus crustose, thin, immersed or thinly powdery to scurfy-granular, effuse, whitish to orange-yellow, often with darker yellow to orange-yellow patches. Ascomata arthonioid apothecia roundish, convex, orange-red-brown to brown-black, usually dull, epruinose, 0.2–0.5 (–0.6) mm diam. Ascomatal section 85–140 µm tall, yellow-orange-red throughout or brown-red in upper hypothecium, K+ magenta and K+ purple with pigments dissolving; epithecium indistinct; hymenium 33–40 µm tall; hypothecium 45–100 µm tall; paraphysoids 0.5–1 (–1.5) µm diam., tips mostly neither swollen nor darkened, a few sometimes with dark walls and apical caps. Ascospores obovoid-ellipsoidal to clavate, 1-septate, hyaline, postmature brown and warted, 11–15 × 4–5 µm. Pycnidia frequent, 40–60 µm diam., wall red-brown, K+ purple; conidia bacilliform or slightly curved, (3.5–) 4–6 × ca 1 µm.