TYPE. UNITED STATES. New Jersey, [on] small limbs in cedar swamps, L.D.v. Schweinitz s.n. (Halsey 1824).

Description. Life form: lichenized fungus.

Thallus foliose, rosette-forming, 2-3 cm broad, loosely attached. Lobes flattish, rounded to laciniate, (1-)2-4(-5) mm wide, with raised tips and undulating margins. Upper surface dark yellowish green or green-gray, sometimes reticulately ridged. Vegetative diaspores absent. Photobiont coccoid green alga; medulla bright yellow. Lower surface smooth to reticulately ridged; rhizines sparse, pale. Ascomata lecanorine apothecia, abundant, submarginal, up to 2-5 mm diam.; disk reddish brown; thalline margin toothed to lobulate. Pycnidia black, sessile, round, mostly on lobe margins; conidia not reported.

Chemistry. Cortex UV-, K-, KC+ yellow, PD- (usnic acid); medulla spot tests negative (pinastric and vulpinic acids).

Substrate and habitat. Corticolous on canopy branches, especially in cedar swamps.

Distribution. Eastern North America; in North Carolina found throughout.

Literature

Halsey, A. (1824) Synoptical view of the lichens growing in the vicinity of the City of New York. Annals of the Lyceum of Natural History of New York 1:[3]-21 (original description as Cetraria viridis).

Hinds, J.W. & P.L. Hinds (2007) The Macrolichens of New England. Memoirs of the New York Botanical Garden No. 96. New York Botanical Garden Press, Bronx, New York. 584 pp.

Lendemer, J.C. & N. Noell. (2018) Delmarva Lichens: An illustrated manual. Memoirs of the Torrey Botanical Society 28: 1-386.