Diorygma sticticum Sutjaritturakan, Kalb & Lücking  

Mycobank MB 517764

Thallus corticolous, up to 5 cm diam., 70–150 µm thick, continuous; surface smooth to uneven, light green; white prothallus sometimes present. Thallus in section with 10–15 µm thick loose upper cortex, irregular algal layer and clusters of calcium oxalate crystals. Lirellae in dense clusters, stellately branched, erumpent, with thick complete thalline margin, 1–3 mm long, 0.15–0.3 mm wide, 0.1 mm high; disc concealed to partly exposed, pale brown but thickly white-pruinose; labia conspicuous, white, the proper excipulum white-pruinose; thalline margin white. Excipulum entire, orange-brown, 15–30 µm thick; laterally covered by corticate algiferous thallus including clusters of crystals; hypothecium prosoplectenchymatous, 10–15 µm high, yellowish; hymenium 60–80 µm high, colourless, clear; epithecium granulose, 5–10 µm high, yellow-brown. Paraphyses unbranched; asci clavate, 60–70 x 10–12 µm. Ascospores 8 per ascus, ellipsoid, submuriform with 3 transverse and 0–1 longitudinal septa per segment, 10–13 x 6–8 µm, 1.5–2 times as long as wide, with thickened septa and rounded lumina, colourless, strongly I+ violet-blue. Secondary chemistry: stictic, hypostictic, and cryptostictic acids.