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''Niebla'' is a genus of yellow-green fruticose lichens that grow on rocks, trees, and shrubs within the fog zone of coastal North America,〔Brodo, I. M., S. D. Sharnoff, and S. Sharnoff. 2001. Lichens of North America. Yale University Press: New Haven.〕 or more narrowly defined to occur on rocks and soil along the Pacific Coast from Mendocino County in California south to Baja California Sur.〔Spjut, R. W. ''Niebla'' and ''Vermilacinia'' (Ramalinaceae) from California and Baja California. Sida Miscellany 14.〕 ==Taxonomy== The genus name is a substitute name〔Rundel, P.W. and P.A. Bowler, 1978. ''Niebla'', a new generic name for ''Desmazieria'' (Ramalinaceae). Mycotaxon 6: 497–499〕 for ''Desmazieria'', a homonym created by Camille Montagne in 1852 who recognized only one species in the genus (''D. homalea'');〔Montagne, D.M. 1852. Diagnoses phycologicae. Ann. Sci. Nat. Sr. 3, 18, 302–319.〕 however, the name ''Desmazeria'', although not spelled exactly the same but nevertheless considered to be the same (homonym),〔 had been given to a genus of grass (Poaceae) by Barthélemy Dumortier in 1822. The earliest name is the one that must be retained unless the later name is conserved, according to the International Code of Botanical Nomenclature. Additionally, the type species name for ''Niebla'' is ''Niebla homalea'', based on the name given to the one species that had been recognized by Montagne for the genus,〔Spjut, R. W. 1995. ''Vermilacinia'' (Ramalinaceae, Lecanorales), a new genus of lichens. In: Flechten Follmann; Contr. Lichen in honor of Gerhard Follmann; F. J. A. Daniels, M. Schulz & J. Peine, eds., Koeltz Scientific Books: Koenigstein, pp. 337–351.〕 not ''Niebla ceruchis''.〔Sérusiaux, E., P. van den Boom, and D. Ertz. 2010. A two-gene phylogeny shows the lichen genus ''Niebla'' (Lecanorales) is endemic to the New World and does not occur in Macaronesia nor in the Mediterranean basin. Fungal Biology 114: 528–37.〕 The genus ''Niebla'' has also been interpreted broadly to include the genus ''Vermilacinia'',〔Bowler, P. and J. Marsh. 2004. ''Niebla''. ‘Lichen Flora of the Greater Sonoran Desert 2’: 368–380〕 although both classifications distinguish species by the presence or absence of chondroid strands. In the broad classification, only three species of ''Niebla'' with chondroid strands are recognized under two arbitrary groups of lichen substances based on their reaction to chemical spot tests〔 of which the most useful in ''Niebla'' appears to be ''para''-phenylenediamine (pd); the nine species in the narrow classification 〔 that contain depsidones (pd+) are all placed under ''N. josecuervoi'' in the broad classification.〔 A second group that contains depsides but also includes the acid-deficient chemotype (''N. homaleoides''), collectively treats 32 species under the name ''N. homalea''. The inclusion of the acid-deficient species in ''N. homalea'' disregards the chemotaxonomic attribute of a pigment associated with species that contain salazinic acid.〔 Both classifications recognize ''N. isidiaescens''. Eleven other species that are treated in ''Vermilacinia'' 〔 are distinguished by thallus morphology. Molecular studies on the North American species of ''Niebla'' and ''Vermilacinia'' have been limited and contradictory. An unpublished study mentioned in a 1995 communication indicated that ''Niebla'' was paraphyletic and that by recognizing ''Vermilacinia'' rendered ''Niebla'' monophyletic.〔http://www.worldbotanical.com/lichens.htm〕 A later study—that reported largely on Old World species of ''Ramalina'' and which included collections of ''Niebla'' and ''Vermilacinia'' species—concluded that ''Niebla'' was monophyletic.〔 However, source material (voucher specimens) cited in the later study for the basis of the DNA analysis of ''Niebla'' was reported to be from California and identified ''N. homalea'' with protocetraric acid and triterpenes. But this chemotype had not been known in ''Niebla'', nor are depsidones known to be present in ''N. homalea'', nor are they present in any species of ''Niebla'' in California;〔 protocetraric acid is found only in ''N. pulchribarbara'', which lacks triterpenes, a rare species that occurs in northern Baja California.〔 In the ''Lichen Flora of the Greater Sonoran Desert Region'', the description given for ''N. homalea''〔 erroneously described the species to have depsidones, including protocetraric acid, which may be confused with salazinic acid when conducting thin-layer chromatography. Salazinic acid is a common lichen substance accessory to triterpenes in species of ''Vermilacinia'', while it may also be noted that the morphology of ''V. laevigata'' is easily confused with that of ''N. homalea''.〔 In view of the controversial classification of this ''Ramalina'' complex of genera, and that many of the species are common along the Pacific coast of North America, it may be helpful to conservationists to have molecular studies be conducted to correlate the different views of the species concepts with their DNA, which should include representative specimens from the entire geographic range of the species before drawing definitive conclusions about their synonymy. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Niebla (lichen)」の詳細全文を読む スポンサード リンク
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