TYPE. GUYANA. Essequibo, in cortice arborum, G. Meyer s.n. (GOET, holotype).

Description. Lichenized fungus.

Thallus foliose, orbicular to suborbicular, up to 75 mm diam., smooth, greenish-white. Lobes linear, appressed with rounded tips. Vegetative diaspores soredia in scattered, laminal to sometimes marginal, flat to hemispherical soralia, yellowish to greenish-white. Photobiont trebouxioid alga. Medulla salmon-colored. Lower surface pale brown to black in center; rhizines frequent, black, simple to irregularly branched. Ascomata lecideine apothecia, rare; disk bluish-black, epruinose, concave; margin thick. Ascospores brown, 2-celled, ellipsoid, 11–15 x 5–6 μm. Pycnidia not found.

Chemistry. Thallus UV+ yellow (lichexanthone), K-; medulla UV-, K+ violet, KC+ reddish, C-, PD-.

Substrate and Habitat. Corticolous on trees.

Distribution. South and North America; in North Carolina found in the Coastal Plan ecoregion.

Literature

Amtoft. A. (2002) Pyxine subcinerea in the eastern United States. The Bryologist 105(2): 270-272.

Aptroot, A. (1987) Pyxinaceae (Lichens). Flora of the Guianas, Series E (Fungi and Lichens) 1: 1-59.

Jungbluth, P. (2010). Estudos taxonômicos em Physcia (Schreb.) Michx. e Pyxine Fr. (Physciaceae, Ascomycota). São Paulo. Tese (doutorado) — Instituto de Botânica da Secretaria de Estado do Meio Ambiente.

Meyer, G. (1818) Primitiae Florae Essequeboensis. 316 pp. (original description as Lecidea albovirens).