TYPE. UNITED STATES. “Trunks, in the mountains of Massachusetts and New Hampshire.” (Tuckerman 1848).
Description.Life form: lichenized fungus.
[Modified from Lendemer & Noell (2018)] Thallus crustose, superficial, thin to thick, blue to blue-gray, corticate, shiny; prothallus indistinct. Vegetative diaspores pustulose-soraliate; soralia small to large, rounded, becoming pustulose, hollow, coarse and breaking apically into granular or soredium-like fragments; soredia coarse, irregular in shape. Photobiont coccoid green alga. Ascomata lecideine apothecia, 0.4–0.8 mm in diameter; disk black, blue-white pruinose; margin prominent, black, pruinose. Exciple with fuscous brown-red pigment inclusions that dissolve and bleed purple-red in K; epihymenium brown, K-; hymenium hyaline to light tan or brown, densely inspersed with oil droplets; hypothecium light to dark brown. Asci 1-spored; ascospores hyaline, 6-celled, thick walled, 65–75 × 20–25 µm.
Chemistry. UV-, K-, KC-, C-, P+ orange-red; pannarin and zeorin.
Substrate and habitat. Corticolous on tree trunks in humid forests.
Distribution. East Asia (Japan, Russian Far East) / eastern North America disjunct; in North Carolina found throughout.
Ezhkin, A.K. (2018) Megalospora porphyritis (Tuck.) R.C. Harris, a new record for Russia. Botanica Pacifica7(2): 143–145.
Lendemer, J.C. & N. Noell. (2018) Delmarva Lichens: An illustrated manual. Memoirs of the Torrey Botanical Society28: 1-386.
Tuckerman, E. (1848) A synopsis of the lichenes of the northern United States and British America. Proceedings of the American Academy of Arts and Sciences1: 195-285 (original description as Biatora porphyritis).