TYPE. “In Alabama America bor. [United States] (Mrs. Hawley).” (Stirton 1881)

Description. Life form: lichenized fungus.

[Modified from Lendemer & Noell (2018)]. Thallus fruticose, erect, shrubby, 0.3-30 cm long, dull yellow-green to green (usnic yellow) thoughout (i.e., base not blackened). Branches divergent, round in section, not inflated, covered with papillae and fibrils of various length. Vegetative diaspores absent. Thallus stratified: photobiont chlorococcoid alga; medulla pink to reddish; axis whitish. Ascomata lecanorine apothecia, abundant, terminal, 0.5-2 cm diam.; disk yellowish brown, concave. Epihymenium hyaline, K-; hymenium hyaline, clear; hypothecium hyaline. Asci 8-spored; ascospores hyaline, simple, ellipsoid, 7-9 x 5-7 μm.

Chemistry. Cortex UV-, K-, KC+ gold, C-, PD- (usnic acid); medulla UV-, K+ dull brownish-orange, KC-, C-, PD+ dingy yellow (norstictic acid).

Substrate and Habitat. Corticolous on hardwoood trees, particularly on canopy branches.

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

Note. Usnea endochrysea is morphologically indistinguishable from the common and widespread U. strigosa, but can be distinguished by slightly smaller ascospores (compared with 9-10 x 5-6 μm in U. strigosa).

Literature

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

Stirton, J. (1881) On the genus Usnea, and another (Eumitra) allied to it. Scottish Naturalist 6: 99-109 (original description).