TYPE. “America Borealis, Alabama, Battler, ad Taxodium (cypress), 1925 A.W. Evans.” (Motyka 1936-1938). UNITED STATES. Alabama, Battler, on cypress, 24.V.1925, A.W. Evans s.n. (FH, TNS, isotypes?).
Description.Life form: lichenized fungus.
[Translated and modified from Motyka (1936-1938)] Thallus fruticose, bushy, ~5 cm high and wide, almost globose, stiff, dark olive green, matte, often repeatedly branched, axils raised and branches diverging. Branches ~1 mm thick, slightly gradually tapering to the tips. Surface continuous or rarely cracked, smooth, lacking papillae but young fibrils often resemble papillae; fibrils abundant, perpendicular to the branch surface, usually ~1-3 mm long, but often intermingled with much longer ones, slightly constricted at the base, subinflated or cylindrical above, abruptly tapering to the tips, obtuse, larger ones rarely branched again. Thallus stratified: cortex ~60 μm thick, chrondroid, yellowish; medulla ~210 μm thick, white; axis ~230 μm diam. Ascomata lecanorine apothecia, numerous, terminal, up to 1 cm diam., +/- flat. Thalline rim marginally fibrillate, smooth to wrinkled underneath; marginal fibrils radiating, mostly shorter than disk diam., slender or slightly curved. Disk +/- flat and slightly wrinkled only in the center, pale fleshy, almost scaly. Epithecium graysih. Asci clavate, 8-spored; ascospores simple, hyaline, ~9 x 6 μm.
Note.Usnea evansii is nearly indiscernible to U. strigosa morphologically, but is distinguished anatomically by the soft cortex and thick, white medulla, reacting K+ red.
Chemistry. Medulla K+ orange-red
Substrate and habitat. Corticolous on branches.
Distribution. Southeastern North America along Gulf and Atlantic coasts; in North Carolina found primarily in the Coastal Plain ecoregion
Motyka, J. (1936-1938) Lichenum generis Usnea studium monographicum, pars systematica 1-2: 1-651 (original description).