Diorygma microsporum M. Cáceres & Lücking  

Mycobank MB 517763

Thallus corticolous, up to 5 cm diam., 50–120 µm thick, continuous; surface smooth to uneven, light greyish green; white prothallus sometimes present. Thallus in section with 5–10 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, 1–5 mm long, 0.15–0.25 mm wide, 0.1 mm high; disc partly exposed, flesh-colored to light red-brown but thickly white-pruinose; labia conspicuous, white, the proper excipulum white-pruinose and crumbling and usually separated from the thalline margin by a split; thalline margin white. Excipulum entire, orange-brown, 15–25 µm thick; laterally covered by corticate algiferous thallus including clusters of crystals; hypothecium prosoplectenchymatous, 10–15 µm high, yellowish; hymenium 60–70 µm high, colourless, clear; epithecium granulose, 5–10 µm high, yellow-brown. Paraphyses unbranched; asci clavate, 60–70 x 12–15 µm. Ascospores 8 per ascus, ellipsoid, submuriform with 3 transverse and 0–1 longitudinal septa per segment, 12–15 x 6–7 µm, 2 times as long as wide, with thickened septa and rounded lumina, colourless, strongly I+ violet-blue. Secondary chemistry: norstictic acid.