TYPE. UNITED STATES. Florida, Seminole County, Sanford, on Quercus, XI.1917, S. Rapp 702 (S, isolectotype).
Life form. Lichenized fungus.
Description. [Modified from Lendemer & Noell 2018] Thallus crustose, brown or indistinct, thin, endophloedal to somewhat epiphloedal, poorly developed; prothallus indistinct. Vegetative diaspores absent. Photobiont Trentepohlia alga. Ascomata lecanorine apothecia, 0.3-0.5 mm diam., sessile, round; disk brownish black, epruinose; margin white, superficially byssoid, epruinose. Exciple hyaline inner, brown outer; epithecium brown, K-; hymenium hyaline, clear; hypothecium hyaline. Asci 8-spored; ascospores hyaline, transversely septate, 5-celled, narrowly fusiform, often curved, 22-26 x 3-4.5 μm. Conidiomata not reported.
Chemistry. Spot tests negative; no substances detected by TLC.
Substrate and habitat. Corticolous on hardwoods coastal forests.
Distribution. Gulf and Atlantic coasts of southeastern North America; in North Carolina found in the Coastal Plain ecoregion.
Literature
Lendemer, J.C. & N. Noell. (2018) Delmarva Lichens: An illustrated manual. Memoirs of the Torrey Botanical Society 28: 1-386.
Zahlbruckner, A. (1930). A New Haematomma from Florida. The Bryologist 33(3): 31–31 (original description as Haematomma rappii).