Chapsa rubropulveracea Hale ex Mangold, Lücking & Lumbsch  

Mycobank MB 517753

Thallus corticolous, up to 5 cm diam., 50–100 µm thick, continuous; surface distinctly farinose, white-grey. Thallus in section lacking upper cortex, with irregular algal layer and abundant clusters of calcium oxalate crystals. Apothecia erumpent, angular-rounded, 0.5–1 mm diam.; disc exposed, red-pruinose; margin lobulate, fused, white-pruinose. Columella absent. Excipulum paraplectenchymatous, 10–20 µm thick, colourless; periphysoids present. Hymenium 50–70 µm high, with a layer of crystalline red pigment above which dissolves in KOH; paraphyses unbranched. Ascospores 8 per ascus, 5–7-septate, 15–20 x 5–6 µm, oblong, with thin to slightly thickened septa and rectangular lumina, colourless, I–. Secondary chemistry: no substances detected with TLC except red pigment on apothecial disc (K+ purple).