A phylogenetic study of Sobralia (Orchidaceae) confirmed the polyphyletic character of the genus. Sobralia also appears to be highly heteromorphic in the morphology, especially considering the position and architecture of inflorescence, lip form and kind of its outgrowths, length and form of stelidia of column. The infrageneric relationship of Sobralia species was revealed by analyses of three DNA markers (nuclear ITS, xdh and plastid matK). The nominal section of the genus appears to be more related with Elleanthus and other genera of Sobralieae than with the remaining species of Sobralia. Sobralia section Sobralia differs from other representatives of the genus by the position and architecture of inflorescence, smaller floral bracts and the morphology of the flowers. We propose a generic rank to the group despite its paraphyletic nature. Nomenclatural consequences of this proposal are briefly discussed. Appropriate transfers to the newly erected genus Brasolia are proposed. A new species, Brasolia floribunda, previously detected by Reichenbach, but never formally described, is validated. Lectotypes for five species and a neotype for the other one are proposed.

To test the taxonomic significance of secondary chemistry (particularly lobaric acid and fatty acids) and pruina in Parmelia ernstiae, P. saxatilis, P. serrana, P. submontana and P. sulcata in Europe, 3684 specimens were analysed morphologically and chemically, and 82 ITS rDNA sequences were prepared. A comparison of the resulting phylogram with the production of secondary metabolites (P. saxatilis group) and the intensity and presence of the thallus pruina (all five species) show that lobaric acid occurs in only three species, P. ernstiae, P. saxatilis and P. serrana, but its presence is variable within them. Fatty acids are restricted to P. ernstiae and P. serrana. All studied species can develop epruinose to strongly pruinose thalli, and therefore pruina is an uninformative character at species level. The traits reliable for the determination of the species are the type of vegetative propagules, their placement on the thallus, and the lobe shape. It was previously suggested that the development of pruina may depend on light intensity, but epruinose and pruinose thalli of the same species were often found growing side by side in exactly the same environmental conditions. Thalli differing in pruina intensity might contain different photobiont strains.

BackgroundThe generic separateness and specific composition of the orchid genus Cyrtochilum was discussed for almost two centuries. Over the years several smaller taxa were segregated from this taxon, but their separateness was recently questioned based on molecular studies outcomes. The aim of our study was to revise concepts of morphological-based generic delimitation in Cyrtochilum-alliance and to compare it with the results of genetic analysis. We used phylogenetic framework in combination with phenetical analysis to provide proposal of the generic delimitation within Cyrtochilum-alliance. Two molecular markers, ITS and matK were used to construct phylogenetic tree. A total of over 5000 herbarium specimens were included in the morphological examination and the phenetical analysis included 29 generative and vegetative characters.ResultsComparative morphology of the previously recognized genera: Buesiella, Dasyglossum, Neodryas, Rusbyella, Siederella and Trigonochilum is presented. A new species within the the latter genus is described. Fourteen new combinations are proposed. The key to the identification of the genera of the Cyrtochilum-alliance and morphological characteristics of each genus are provided.ConclusionsA total of six separated genera are recognized within Cyrtochilum-alliance. The reasons of the incompatibility between morphological differences observed within studied taxa and phylogenetic tree are argued and the taxonomic implications of such inconsistency, resulting in fragmentation or lumping of taxonomic units, are discussed.Electronic supplementary materialThe online version of this article (doi:10.1186/s40529-017-0164-z) contains supplementary material, which is available to authorized users.

The results of a revision of the orchid genus Andinia are presented. The proposed classification is based on outcomes of morphological and molecular studies. Additionally, the similarity of the climatic niches occupied by representatives of the Andinia-complex was calculated and visualized. The highest number of Andinia representatives is found in the Eastern Cordillera real montane forests, while Neooreophilus species are found in two ecoregions—the Eastern Cordillera real montane forests, and the Northwestern Andes. According to the level of endemism, a very unique orchid flora was noted in the Guajira–Barranquilla xeric scrub ecoregion, as well as in the Isthmian-Pacific and the Ucayali moist forests, where single endemic species occur. In the proposed classification, nine genera are recognized within the Andinia-complex, three of which (Xenosiella, Chicalia, and Minuscula) are described in this paper. A key to the identification of all genera is provided. Additionally, sections Amplectentes and Bilamellatae of Neooreophilus are elevated to the subgeneric rank, and subgenus Aenigma is here considered as a separate genus. A complete list of representatives of each taxon is provided, and new combinations are proposed accordingly. A new species of Neooreophilus from Colombia is described.

The location of possible glacial refugia of six Apostasioideae representatives is estimated based on ecological niche modeling analysis. The distribution of their suitable niches during the last glacial maximum (LGM) is compared with their current potential and documented geographical ranges. The climatic factors limiting the studied species occurrences are evaluated and the niche overlap between the studied orchids is assessed and discussed. The predicted niche occupancy profiles and reconstruction of ancestral climatic tolerances suggest high level of phylogenetic niche conservatism within Apostasioideae.

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Despite the clear circumscription of tribe Sobralieae (Orchidaceae), its internal relationships are still dubious. The recently delimited genus Brasolia, based on previous Sobralia species, is now assumed to be paraphyletic, with a third genus, Elleanthus, nested in it. The morphology of these three genera is significantly different, indicating the necessity of new data for a better genera delimitation. Though morphology and molecular data are available, cytogenetics data for Sobralieae is restricted to two Sobralia and one Elleanthus species. Aiming to evaluate the potential of cytogenetic data for Brasolia-Elleanthus-Sobralia genera delimitation, we present chromosome number and genome size data for 21 and 20 species, respectively, and used such data to infer the pattern of karyotype evolution in these genera. The analysis allowed us to infer x = 24 as the base chromosome number and genome size of average 1C-value of 5.0 pg for the common ancestor of Brasolia-Elleanthus-Sobralia. The recurrent descending dysploidy in Sobralieae and the punctual genome upsize suggest a recent diversification in Sobralieae but did not allow differing between Brasolia and Sobralia. However, the basal position of tribe Sobralieae in the subfamily Epidendroideae makes this tribe of interest to further studies clarifying the internal delimitation and pattern of karyotype evolution.

Ochrolechia kerguelensis Ertz & Kukwa is described as new to science from the subantarctic islands of Kerguelen. It is characterized by pruinose ascomata, usually 4-spored asci, large ascospores of 50–90 × 32–56 µm, the production of gyrophoric acid only in the apothecia and the lack of variolaric acid. A photobiont with cells containing orange guttules such as in trentepohlioid algae is recorded for the first time in the genus Ochrolechia, being present in O. austroamericana and O. kerguelensis. Ochrolechia antarctica is reinstated from the synonymy of O. parella and treated as a distinct species. Chemical and morphological differences between these taxa are discussed. Ochrolechia chilensis and O. deceptionis are treated as synonyms of O. antarctica. The phylogenetic placement of O. antarctica, O. austroamericana and O. kerguelensis is investigated using mtSSU rDNA sequences and a Bayesian analysis. A key to all fertile, saxicolous Ochrolechia species with a C+ red epihymenium occurring in the Southern Hemisphere is presented.