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Usnea subelegans (Vain.) Motyka 1933
Family: Parmeliaceae
Usnea subelegans image
Philippe Clerc  
Thallus: shrubby-erect, 2-8 cm long branching: isotomic- to anisotomic-dichotomous basal part: paler or of the same color as main branches, without conspicuous cracks branches: tapering or irregular; lateral branches: not or only slightly narrowed at attachment points segments: terete and cylindrical papillae: absent tubercles: absent fibercles: irregularly present fibrils: 1-2(-3) mm long, usually conspicuous, spinulous, not easily breaking away, dense on the whole length of the branches giving to the the thallus a dense spinulous appearance isidiomorphs: absent cortex: thin (5-9%), glossy, not conspicuously cracked medulla: large, compact to dense, often peripherally pale pink axis: moderately thick, often peripherally pale pink Apothecia: 2-15 mm in diam., mainly lateral, less commonly terminal ascospores: ellipsoid, 8-10 x 5-6 ┬Ám long Spot tests: medulla K+ yellow turning red, C-, KC-, P+ orangish yellow Secondary metabolites: cortex with usnic acid; medulla with norstictic (major), galbinic (major) and salazinic (major) acids. Substrate and ecology: on bark of small deciduous trees in thorn forest at the top of a small volcanic mountain at 600 m of altitude World distribution: Mexico Sonoran distribution: northern Sinaloa. Notes: Usnea subelegans is very close to U. dasaea, from which it differs by its reproduction strategy and the fibrils that are not easily broken away, and hence densely cover the whole thallus.