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 Add this item to the list  833376 Original description
Remarks (public):Ecology and distribution: Known only from the Galapagos; occurs in the coastal to the transition zone, typically in ±exposed, sunny habitats, often on dry bark or decorticated wood of native trees and shrubs (Bursera graveolens, Cordia lutea) and cactus pads (Opuntia megasperma var. orientalis). Notes: The new species belongs to a complex group of similar taxa that have been treated in detail by Printzen (2001). It is described here as new, for although the Galapagos specimens share many characteristics with L. substrobilina Printzen, L. confusa Alm., and L. perconfusa Printzen, but upon closer examination they can be shown to differ from all of these species. Lecanora confusoides is most similar to L. substrobilina. The two species have similarly sized ascospores and a well developed proper exciple surrounded by a distinct, thalline exciple. However, the thalli of L. substrobilina remain esorediate, whereas the granules of L. confusoides typically burst open to form blastidiate soredia. Older apothecial discs of L. confusoides regularly become olivaceous due to an aeruginose pigment, and on treatment with K this aeruginose pigment intensifies, turning almost black. Such discoloration is rarely observed in L. substrobilina. Printzen (2001) reported aggregations of soredia (“consoredia”) for L. perconfusa. The coarse soredia of L. confusoides are not formed by secondary aggregation. Instead they burst from minutely branched or granular thallus protuberances, breaking open to extrude soredia, a process perhaps best compared to the formation of blastidia. The thallus of L. perconfusa often lacks xanthones or contains them in lower concentrations than observed in L. confusoides. In addition, L. perconfusa has longer and more elongate ascospores than L. confusoides. Older apothecia in L. confusa often develop an olivaceous to blackish tinge similar to that found in L. confusoides. This discoloration of the apothecial disc is not unusual in this species group and is most pronounced in L. sublivescens, a temperate species which lacks xanthones. Lecanora confusa is not known from the tropics and in western North America south of 28°N it is usually replaced by L. perconfusa Printzen (2001). The ascospores of L. confusa are on average broader (4.0–5.7 µm wide) than those of L. confusoides. Thus L. confusoides is characterized by having some apothecia that are distinctly discolored, small ascospores, and epruinose thalli that invariably contain xanthones. Chemically L. confusa, L. confusoides, L. perconfusa and L. substrobilina are quite similar, but specimens of L. confusoides frequently lack usnic acid. Superficially, specimens of Amandinea efflorescens var. pseudohypopelidna Marbach, a taxon also present in Galapagos, can appear quite similar to sterile material of L. confusoides. However, the thalli of the Amandinea are usually characterized by a conspicuous, compact black prothallus and its soredia are not formed from blastidiate protuberances. In the field the two species can easily be distinguished, the Lecanora has a characteristic greenish yellow color, A. efflorescens var. pseudohypopelidna is typically pinkish, a color cast lost when specimens are stored for prolonged periods in the herbarium. 
Description type:Original description 
Description:Thallus corticolous or lignicolous, thin to moderately thickened, often at least in part endosubstratal, rimose-areolate; surface dull yellowish green to greenish beige, matt, epruinose, verruculose, sparsely to abundantly covered by irregular corticate granules [50–100 µm in diam.], bursting open to form poorly delimited, blastidiate soredia [25–35 µm in diam.]. Apothecia sparse to numerous, irregular to flexuose in outline, often densely crowded and ±deformed by mutual pressure, 0.5–1.3(–1.7) mm in diam., ±immersed to adnate, rarely sessile, biatorine to ±lecanorine, initially with a distinct proper margin that becomes excluded and successively replaced by a granular-blastidiate thalline margin, concolorous with the thallus, epruinose; disc plane to  convex, often uneven, pale brown to beige, increasingly discolored with age, olivaceous to blackened, sparsely covered by a fine, whitish pruina; hymenium hyaline, not inspersed; epihymenium with small orange brown granules, soluble in K, lacking distinct crystals, fuscous brown (elachista-brown: dissolving in K, HCl± dull greenish, N−), occasionally in parts or entirely discolored by a diffuse aeruginose pigment (cinereorufa-green: intensifying in K, HCl+ bluish green, N+ reddish violet); proper exciple distinct, hyaline within, outer side concolorous with the epihymenium and covered with small orange brown granules soluble in K, granules at the base of the exciple often very abundant, often ±radiating along the hyphae from the lower inner to the lower outer part of the exciple; thalline exciple poorly to ±well developed, embracing the proper exciple from below, frequently disintegrating into blastidiate soredia; subhymenium and hypothecium hyaline; ascus clavate, Lecanora-type; ascospores 8/ascus, colorless, simple, rarely with one indistinct pseudoseptum, ellipsoid to narrowly ellipsoid or ±citriform (apically ±pointed), (6.5−)7.9−11.0(−13.0) x (3.5−)3.7−4.7(−5.0) µm (n = 30). Pycnidia immersed, ostiole brown, wall hyaline; conidia filiform 15−25 x c. 0.8−1 µm (n = 15). Chemistry: Thallus cortex including apothecial margin P, C+ orange, KC+ orange, K- yellowish brown, UV- (dull, xanthones possibly restricted to the medulla); containing ±usnic acid [major], thiophanic acid [major], arthothelin [minor], 4-chloronorlichexanthone [minor], 5-chloronorlichexanthone [minor], ±zeorin [trace], 4,5-dichloronorlichexanthone [trace]. 
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