A first integrative survey of the genus Usnea in the southern Philippines, taking into account morphological, anatomical, chemical and molecular characters, resulted in the recognition of 20 taxa, including three species new to science: Usnea angulata Ach., U. baileyi (Stirt.) Zahlbr., U. bismolliuscula Zahlbr., U. brasiliensis (Zahlbr.) Motyka, U. confusa Asah., U. croceorubescens Stirt., U. dasaea Stirt., U. himalayana C. Bab., U. krogiana P. Clerc, U. longissima Ach., U. nidifica Taylor, U. norsticornuta A. Gerlach & P. Clerc sp. nov. (characterized by a moderately thick cortex and by the presence of norstictic acid), U. paleograndisora A. Gerlach & P. Clerc sp. nov. (characterized by an orange subcortical pigmentation in the medulla, with enlarging soralia and a moderately thick and shiny cortex), U. pectinata Taylor, U. pygmoidea (Asahina) Y. Ohmura, U. rubicunda Stirt., U. rubrotincta (Stirt.) Zahlbr., U. spinulifera (Vain.) Motyka, U. subscabrosa Motyka and U. yoshihitoi P. Clerc & A. Gerlach sp. nov. (characterized by a lax medulla with non-conglutinated hyphae). Usnea krogiana is a new record for Asia; Usnea brasiliensis, Usnea confusa and U. croceorubescens are new records for the Philippines. This is the first phylogenetic study to include DNA sequences of Usnea from the Philippines. Molecular data from the ITS rDNA (76 newly generated sequences) are presented for most taxa except for U. himalayana, U. longissima and U. subscabrosa. At least six further taxa remain unidentified, awaiting the collection of additional specimens.

This study investigated the molecular, chemical and morphological variation in the Usnea pectinata aggregate using 42 specimens, 22 from Tanzania and 20 from São Tomé and Príncipe. A total of 31 sequences (13 ITS, 13 nuLSU and 5 RPB1) were generated. The results are presented in two phylogenies: first a three-markers ‘backbone’ phylogeny for the U. pectinata aggregate, where six distinct, strongly supported subclades indicate considerable genetic variation in the dataset; and second, an ITS phylogeny with 47 terminals along with a mapping of morphological and chemistry data. Several well-supported monophyletic clades were recovered in both phylogenies and these may well represent separate species in the complex referred to here as the U. pectinata aggregate. Three morphotypes characterized by axis pigmentation and four by branch shape were noted. Six chemotypes were observed.

An investigation of the genus Usnea, in the biodiversity hotspot of the Republic of São Tomé and Príncipe in tropical West Africa, is presented here. Fifteen species, or species aggregates, were recorded for the islands: Usnea articulata aggr., Usnea baileyi (Stirt.) Zahlbr., Usnea beckeri P. Clerc & Nadel, Usnea bicolorata Motyka, Usnea erinacea aggr., Usnea exasperata (Müll. Arg.) Motyka, Usnea firmula (Stirt.) Motyka, Usnea krogiana P. Clerc, Usnea longiciliata P. Clerc & Nadel, Usnea nodulosa Swinscow & Krog, Usnea pectinata aggr., Usnea sorediosula Motyka, Usnea submollis J. Steiner, and two undetermined species. Two species of lichen are described as new to science: U. beckeri and U. longiciliata. Both species are characterized by a dense and brittle, dark green thallus, the presence of apothecia surrounded by long cilia-like fibrils, a lack of soredia, and the presence of two unknown substances; however, whereas U. beckeri has a pendant growth form and can reach 25 cm in length, U. longiciliata is differentiated by a shrubby growth form of less than 6 cm. These two species also have different ascospore dimensions. A molecular phylogenetic analysis is presented that lends support to their description as new species. Additionally, Usnea krogiana is noted as new to continental Africa and nine Usnea species or aggregates are noted as new to the Islands of São Tomé and Príncipe in the Gulf of Guinea.

Using molecular data to delimit species or reconstruct their evolutionary history is now widely used across all organisms. However, such analyses can suffer from poor or false specimen identifications leading to incorrect conclusions. Here we show that the use of misidentified specimens in a phylogenetic framework resulted in questionable conclusions in a previously published study (Mark et al. 2016). Using morphological, chemical and statistical analyses on the specimens used in that study, we found support for Usnea barbata and U. dasopoga being morphologically and anatomically distinct species with separate clusters in the molecular phylogeny. Furthermore, our revision of specimen identifications refutes the synonymization of U. substerilis with U. lapponica. In conclusion, we discuss the issue of correct identification of voucher specimens in DNA databases and conclude with some general suggestions to avoid false specimen identifications in phylogenetic studies.

Usnea viktoriana P. Clerc & Otte is described as new. It is characterized by the presence of alectorialic acid as major secondary compound mainly present in the aggregated efflorescent soralia with long isidiofibrils. Usnea parafloridana K. Mark, Will-Wolf & Randlane is synonymized with U. praetervisa (Asahina) P. Clerc. Both U. viktoriana and U. praetervisa are supported by molecular analysis. A key to the shrubby-subpendulous sorediate Usnea species in Europe is provided.

Seventeen corticolous shrubby apotheciate Usnea species without vegetative propagules are reported from Brazil, including five species that are new to science: Usnea aurantiaca-parvula A. Gerlach & P. Clerc (characterized by an orange medulla and lageniform spinulose fibrils), U. cirrosa Motyka, U. cladocarpa Fée (syn. nov.: U. ramillosa Motyka), U. concinna Stirton (lectotype designated here, syn. nov. U. radiata Stirton, U. florida var. scabrosa Zahlbr.), U. cristatula Motyka, U. erinacea Vain., U. fleigiae A. Gerlach & P. Clerc (characterized by large spores and a thin, lax medulla), U. grandispora A. Gerlach & P. Clerc (characterized by large spores, a black base and protocetraric or salazinic acids in the medulla), U. kalbiana P. Clerc & A. Gerlach (characterized by a vitreous cortex and annular cracks in the basal part), U. lunaria Motyka, U. meridionalis Zahlbr. (syn. nov.: U. michauxii I. I. Tav.), Usnea cf. moreliana Motyka, U. parvula Motyka, U. steineri Zahlbr, U. subelegans (Vain.) B. de Lesd. (lectotype designated here), U. subparvula A. Gerlach & P. Clerc (characterized by spinulose fibrils and protocetraric acid in the medulla) and one as yet unidentified species (named Usnea sp. 1). Usnea cirrosa, U. cristatula and U. erinacea are new records for Brazil. A full description with morphological, anatomical (CMA and ascospores) and chemical features (TLC), as well as geographical distribution, is provided for each species along with an identification key to all species reported. Molecular data from the ITS rDNA, RPB1 and Mcm7 markers are present for most taxa, except for U. concinna, U. cristatula, U. kalbiana, U. lunaria, U. cf. moreliana and U. subelegans.

Usnea is a cosmopolitan genus of lichen-forming Ascomycota (Parmeliaceae, Lecanorales). This hyperdiverse genus remains poorly known, especially in tropical regions, and recent efforts have been made to clarify the species concepts and describe the diversity of species. We describe five new species from tropical South America based on morphological and chemical features supported by molecular data from the ITS rDNA, nuLSU, RPB1 and Mcm7 markers. Usnea clerciana is a Galapagos endemic characterized by inflated branches holding elongated tubercles, excavate soralia and/or apothecia. Usnea aranea and U. subaranea share inflated branches with numerous papillae and a loose arachnoid medulla, but differ in the minute and irregular soralia in U. aranea, that are circular and excavate in U. subaranea. Usnea rubriglabrata and U. subglabrata are characterized by inflated branches with excavate soralia, with a reddish cortex pigmentation in U. rubriglabrata that is lacking in U. subglabrata. Usnea aranea, U. rubriglabrata, U. subaranea and U. subglabrata are so far endemic to continental South America; the three former species are closely related and cluster in a highly supported clade, characterized by species distributed in the tropical Andes. New records for the region are provided and U. moreliana is resurrected, corresponding to the valid name for U. rubricornuta.

Recently collected specimens of the crustose lichen Melaspilea demissa from south-eastern USA have been compared with those of Melaspilea spp. previously determined from North America. A review of both the historical and contemporary treatments of this species is provided. A lectotype was selected from the type collection of M. demissa in FH and is here proposed as it best matches incomplete citations in the original treatment. We also discuss the nomenclatural and taxonomic status of the name Opegrapha cymbiformis var. deformis (considered a synonym of M. gibberulosa). North American specimens of M. gibberulosa were found to be misidentifications, as were specimens attributed to M. lentiginosula, M. mesophlebia and M. octomera. We therefore recommend that these species be removed from the North American lichen checklist. We also present a key to North American Melaspilea.

The diversity of pendulous Usnea species in tropical South America (Bolivia, Brazil, Colombia, Ecuador, Paraguay, Peru and Venezuela) and the Galapagos Islands is discussed with reference to 23 species. Usnea crenulata Truong & Clerc is newly described. Usnea articulata, U. deformis, U. dimorpha, U. geissleriana, U. merrillii, U. perhispidella, U. sanctaeritae, U. subflammea and U. transitoria are newly reported for South America. Modern descriptions are provided for Usnea amabilis, U. arthroclada, U. dodgei, U. humboldtii and U. regia. We propose to reject the synonymy of U. hesperina with U. schadenbergiana, and the valid name for U. hesperina is therefore U. subgracilis. Distinct patterns of unidentified triterpenoids have been detected by thin-layer chromatography and are used to characterize several species within this group. The morphology, branch anatomy, chemistry, ecology and distribution of each species are given, together with an identification key.

Eumitrioid Usnea species are characterized by a tubular central axis throughout the entire thallus. Four species were identified in South America: Usnea baileyi is a (sub-) tropical species occurring both in continental South America and the Galapagos; U. perplectata has a scattered distribution worldwide and occurs in continental South America, mainly on the eastern range; U. flaveola and the newly described species U. subflaveola are both so far endemic to the Neotropical Andes. Distinct chemotypes, as well as anatomical characters, such as the thickness ratio of the medulla or the presence of medullar pigmentation, are diagnostic in delimiting these species. A detailed description of the species is provided together with an identification key.

In tropical South America (Venezuela, Colombia, Ecuador, Peru, Bolivia and Brazil), we investigated the diversity of Usnea species with a pigmented, C+ yellow medulla. Four species are treated: the sorediate U. ceratina and U. entoviolata, the latter being new for South America, and the non-sorediate U. cristatula and U. flavorubescens, the latter being newly described here. A detailed description is provided for each species together with an identification key.

The purpose of the present study was to establish the prebiotic effect of a new xylo-oligosaccharide (XOS) and of an inulin-and-XOS mixture (INU–XOS) and to determine their effect on endotoxaemia (lipopolysaccharides (LPS)) and immune parameters. In this randomised, parallel, placebo-controlled, double-blind study, sixty healthy volunteers were randomly assigned to three groups, receiving either 5 g XOS, INU–XOS (3 g inulin +1 g XOS) or an equivalent weight of wheat maltodextrin (placebo) during 4 weeks. Faecal samples were collected to assess the effects of these products on microbiota, as well as SCFA composition, enzymatic activities and secretory IgA production. Circulating LPS was measured in plasma samples, and whole blood was incubated with LPS to measure cytokine expression. Consumption of XOS alone increased the faecal concentrations of Bifidobacterium and butyrate and activities of α-glucosidase and β-glucuronidase, while decreasing the concentrations of acetate and p-cresol. Consumption of XOS in combination with inulin did not decrease the concentrations of acetate and p-cresol, but increased in addition the faecal concentrations of total SCFA and propionate. Furthermore, consumption of XOS in combination with inulin decreased LPS concentrations in blood and attenuated LPS-induced increases in gene expression in IL-1β and LPS-induced decreases in gene expression in IL-13 in blood. In conclusion, consumption of XOS alone or in combination with inulin results in beneficial albeit different changes in the intestinal microbiome on a high-fat diet. In addition, consumption of XOS in combination with inulin attenuates the proinflammatory effects of a high-fat diet in the blood of healthy subjects.

The study of the type and additional material of Buellia andicola, B. hypophana and B. reagens has shown that these taxa are conspecific with B. thiopoliza. Buellia thiopoliza is a muscicolous species growing at middle to high altitudes in the mountains of both hemispheres. It is easily recognized by its K+ purple-red yellow pigment mainly concentrated in the hypothecium, and by the presence of xanthones in the thallus and the apothecial tissues. The new combination Tetramelas thiopolizus is proposed. A key to all known Tetramelas species is included. The also muscicolous Buellia hypoleuca is reduced to synonymy with Phaeorrhiza sareptana var. sphaerocarpa.

This study investigates how anatomical characters can be used to differentiate two morphologically close species, Melanohalea olivacea (L.) O. Blanco et al. and M. septentrionalis (Lynge) O. Blanco et al. Although the two species are morphologically differentiated, mainly based on the position and shape of pseudocyphellae on the lobes, poorly-developed specimens can be difficult to identify based on morphology alone. For example, in Switzerland, both species are at the south-west limit of their distribution range and most specimens are small and not fully developed. In such cases, anatomical characters are particularly useful in separating the two species. Five anatomical characters were studied: spore length and width; hymenium, subhymenium and hypothecium height. A nested ANOVA showed that variation of spore length was 155 times greater between species than between individuals of the same species, itself 5 times higher than within individuals. In a Principal Component Analysis, despite a substantial variation of the anatomical characters within both species, a significant species differentiation appeared distinctly on the first axis (P < 0·001), which accounted for 62·35% of the total variance, and the type specimens nested within each species. Finally, a Discriminant Linear Analysis assigned 100% of the individuals to their species class, the best predictors to discriminate between the two species being subhymenium height and spore length. These characters proved to be powerful in identifying specimens with a poorly-developed morphology and confirmed the presence of M. olivacea in Switzerland.

The genus Usnea is a conspicuous component of the macrolichen vegetation in Macaronesia. Ten species are recognized in the Azorean archipelago: Usnea cornuta Körb., U. esperantiana P. Clerc, U. flammea Stirt., U. geissleriana P. Clerc sp. nov., U. krogiana P. Clerc sp. nov., U. macaronesica P. Clerc sp. nov., U. rubicunda Stirt., U. silesiaca Motyka, U. subflammea P. Clerc sp. nov., and U. subscabrosa Motyka. All these species occur in the Canary Islands as well. Descriptive, chemical, ecological and distributional data for each species are provided. Species that have been recorded once for the Azores but not seen, or that are doubtful or excluded in this work, are briefly discussed.

Fifteen species of Usnea are recorded from Iberian cork-oak forests: U. ceratina, U. comma, U. dasaea, U. esperantiana, U. flammea, U. fulvoreagens, U. glabrata, U. hirta, U. mutabilis, U. rubicunda, U. subcornuta, U. subfloridana U. subscabrosa, U. substerilis and U. wasmuthii. A key for these species is provided. Details of morphology, chemistry, distribution, ecology and taxonomy are discussed. Usnea dasaea is reported as new to the Iberian Peninsula. New chemotypes of U. fulvoreagens (with squamatic acid) and U. wasmuthii (with psoromic acid) have been identified. Distribution maps of U. dasaeaand U. subcornuta in Europe are presented. A new combination, Usnea subfloridana subsp. praetervisa (Asahina) P. Clerc, is proposed.

Practically most of the taxonomists working on vascular plants and fungi are using the so-called taxonomic species concept, relying largely on morphological criteria or other observable patterns of discontinuity and assuming that these patterns are reflecting the underlying genetic integrity of species. Such a concept is described in detail here for the genus Usnea. The typologicalview versus the populational view of species are discussed. The diagnostic value of characters used by previous and recent taxonomists of the genus is analysed. The fact that Usnea has such a bad taxonomic reputation is discussed. The use by J. Motyka, author of the world monograph published in the thirties, of characters that are strongly modified by environmental factors together with a typological view of species are thought to be mainly responsible for this. More than 770 names have been published worldwide so far and it is suggested that around 50% are to be considered as synonyms.

Usnea quercina Bystrek & Gòrzynska, based on heterogeneous type material, is lectotypified and becomes a synonym of U. wirthii P. Clerc. Usnea wirthii is new for South America. A distribution map of U. madeirensis Motyka (Syn. U. silesiaca Motyka) in Europe is given. Usnea hesperina Motyka (Syn. U. elongate Motyka, U. schadenbergiana Göpp & Stein, U. subgracilis Vain., U. subplicata (Vain.) Motyka) is new for Africa, Asia and South America. Usnea hirta (L.) F. H. Wigg. (Syn. U. corrugate Motyka, U. foveata Vain., U. leprosa Motyka) is new for Africa. Usnea subscabrosa Nyl. ex Motyka (Syn. U. santae-annae Motyka) is new for South America. The holotype of U. marocana Motyka (=U. mutabilis Stirt.) was found in LBL.

A simple DNA extraction method is described, applicable to many different kinds of lichens. The method involves the use of the detergents DTAB and CTAB and yields DNA that can be directly amplified with the polymerase chain reaction or digested with restriction enzymes