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 Add this item to the list  833372 Original description
   
Remarks (public):Etymology: Named in honor of Charles Darwin and the Charles Darwin Foundation. Ecology and Distribution: Known only from the Galapagos; a few collections from semi-shaded basalt tuff. Notes. This species is treated here as a member of the L. subfusca-group because of its apothecial anatomy. The thalli have a distinctly granular-blastidiate surface, which is unusual. No species with a similar thallus has previously been reported from South America (Guderley 1999). 
Description type:Original description 
Description:Thallus saxicolous, thin, rimose-areolate to verruculose areolate, areoles closely adjoining but not interlocked; surface pale white to ivory, roughened, matt, epruinose, in large parts forming blastidiate, pseudocorticate granules which irregularly disintegrate into large patches of ecorticate, often confluent soredia; prothallus weakly developed, powdery arachnoid to compact, indistinct. Apothecia numerous, scattered, circular to slightly irregular in outline, 0.1–0.5 mm in diam., adnate to soon sessile, distinctly lecanorine, margin persistent, smooth to soon strongly granular-verruculose, granules irregularly forming soredia, disc plane to convex, deep mahogany brown, epruinose; hymenium hyaline, not inspersed; epihymenium lacking crystals, with a diffuse, pale yellowish orange pigment (cf. arceutina-yellow: fading reddish yellow in K, HCl+ pale yellow, N± fading), epihymenium lacking crystals, with a diffuse reddish brown pigment (arnoldiana-brown: K+ dull brown, HCl+ reddish brown, N−), pigment ±persistent, although fading in K (glabrata-type); proper exciple thin, indistinct, with few crystals; thalline exciple thick, irregularly disintegrating, with abundant small crystals obscuring few larger ones, only the small crystals soluble in K, the larger ones persistent (melacarpella-type); subhymenium and hypothecium hyaline; ascospores 8/ascus, simple, ellipsoid, (10.8–)11.3–14.6(–16.7) × (4.9–)5.8–7.6(–8.8) µm (n = 30). Pycnidia immersed, ostiole brown, wall hyaline; conidia short filiform, curved, 16–20  c. 01.9–1.5 µm (n = 10). Chemistry: Thallus cortex P+ yellow, K+ orange, KC+ orange, C+ orange, UV+ dull orange; with atranorin [major], zeorin [major], unknown terpenes [minor], 3-O-methylthiophanic acid [minor], thiophanic acid [major]. 
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