TYPE. UNITED STATES. Florida, 1885, E.D. Mead s.n. [FH-Tuck, lectotype selected by Ekman (1996)].
Life form. lichenized fungus
Description. Thallus crustose, blue-green to green or brown-green, continuous, thin and film-like to somewhat scurfy and poorly developed, giving the appearance of a leprose crust. Prothallus indistinct or a thin network of white fibrous hyphae, typically only visible near the thallus margins. Vegetative diaspores absent. Photobiont coccoid green alga (Chlorococcaceae), cells 5 – 8 μm diam. Ascomata biatorine apothecia, scattered, 0.2–0.4 mm diam., pale yellowish to brownish, often variable; disk epruinose, plane; margin white, byssoid, a variably developed layer of tangled fungal hyphae giving the appearance of white cotton fuzz, rarely excluded or absent. Exciple hyaline; epihymenium hyaline to somewhat brownish; hymenium hyaline, not inspersed; paraphyses conglutinate; hypothecium pale yellow. Asci 8-spored; ascospores hyaline, 4-celled, fusiform to narrowly ellipsoid, cells of equal size, 10–15 × 2–4 μm. Conidiomata not reported.
Substrate and habitat. Corticolous on hardwood trees in swamps and humid forests as well as humid microhabitats in upland forests.
Distribution. Coastal Plain of southeastern North America from Louisiana to the Delmarva peninsula of Maryland and Delaware, USA; in North Carolina found throughout.
Literature
Ekman, S. (1996) The corticolous and lignicolous species of Bacidia and Bacidina in North America. Opera Botanica 127: 1-146.
Lendemer, J. & N. Noell (2018) Delmarva Lichens: an illustrated manual. Memoirs of the Torrey Botanical Society28: 1-350.
Tuckerman, E. (1888) A synopsis of the North American lichens. Part. II. Comprising the Lecideacei, and (in part) the Graphidacei. New Bedford, Mass. 176 pp. (original description as Biatora meadii).