TYPE. “Habitat in nova Scotia.” (Acharius 1803)

Description. Life form: lichenized fungus.

Thallus pendulous, 10-30 mm, base not darkened, branching in uneven dichotomies with some perpendicular side branches; primary branches uniformly slender, up to 0.4 mm diam., segmented with conspicuous, somewhat swollen, white annulations, round in cross section; secondary branches sparse. Vegetative diaspores absent. Surface smooth, greenish or yellow-green. Cortex thin (9-12%); medulla white, dense, almost powdery (16-21%); axis reddish to brown, rarely white (37-50%). Photobiont chlorococcoid alga. Ascomata not reported.

Chemistry. Three chemotypes are recognized by Lendemer & Noell (2018):

Chemotype I: Cortex UV-, K-, KC+ yellow, C-, PD-; medulla UV+ dull blue-white, K-, KC+ dirty pinkish, CK+ strong yellow-orange, C-, P+ orange; usnic, diffractaic, and constictic acids.

Chemotype II: Cortex UV-, K-, KC+ yellow, C-, PD-; medulla UV+ dull blue-white, K-, KC+ dirty pinkish, CK+ strong yellow-orange, C-, PD-; usnic and diffractaic acids.

Chemotype III: Cortex UV-, K-, KC+ yellow, C-, PD-; medulla UV-, K-, KC+ dirty pinkish, CK-, C-, PD+ orange; usnic and constictic acids.

Substrate and Habitat. Corticolous on branches in relatively open sites

Distribution. Central to North America, Caribbean; in North Carolina found throughout.

Literature

Acharius, E. (1803) Methodus qua Omnes Detectos Lichenes Secundum Organa Carpomorpha ad Genera, Species et Varietates Redigere atque Observationibus Illustrare Tentavit Erik Acharius. 394 pp. (original description).

Brodo, I.M., S. Duran Sharnoff & S. Sharnoff. (2001) Lichens of North America. Yale University Press, New Haven & London. 795 pp.

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