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Chelystachya, a new genus of the subtribe Polystachyinae (Orchidaceae)A new genus of Orchidaceae (Polystachyinae),ChelystachyaMytnik & Szlach. is described and illustrated basing on results of molecular and morphological studies. It is related toPolystachyaHook. but is distinct in having large, single-noded, spherical, succulent pseudobulbs flattened on the substratum, pendent and densely pubescent inflorescence, lowermost lip, and lip veins directed to the lip base. Results of phylogenetic analyses based on plastid markers validate the reason for a new genus. Keys for determination of all genera of the subtribe Polystachyinae and both species ofChelystachyaare included. Two new combinations are made. A comprehensive description and full synonymy, as well as detailed ecological, phenological and distribution data and a list of 125 examined specimens are provided for each taxon treated. BecausePolystachya affinisLindl. is considered a holotype ofPolystachyaHook. sect.AffinesKraenzl., this name is automatically a synonym of the newly introduced generic nameChelystachya. Other species of the former sectionAffinesare classified within the sectionHumiles.

Results of molecular analysis compared with morphological studies were used for reclassification of the Angraecumalliance (Orchidaceae). For the purpose of this study we sequenced the ITS region (ITS1-5.8S-ITS2) of nrDNA representing nuclear genome and the plastid region trnL-F (including intron of trnL gene and trnL-trnF intergenic spacer). The ITS matrix includes 97 samples representing 86 species and the trnL-F matrix includes 94 samples representing 86 species. We focus mainly on the genus Angraecum, however the other genera of Angraecinae are also included (Aeranthes, Campylocentrum, Dendrophylax, Cryptopus, Calyptrochilum, Lemurorchis, Jumellea, Neobathiea, Oeonia, Oeoniella, Sobennikoffia). Additional 43 sequences, including an outgroup (Polystachya modesta) and other representatives of the subtribes Aeridinae (Aerides) and Aerangidinae (Aerangis, Angraecopsis, Erasanthe, Solenangis), were obtained from NCBI resources. Bayesian analysis using MrBayes 3.1.2 on the combined ITS/trnL-F matrix were performed. The monophyly of Angraecinae with an inclusion of Aerangidinae is highly supported by both methods (93 BP/100 PP). The Angraecoid taxa formed two well supported clades, namely clade I (89 BP/100 PP) and clade II (84 BP/100 PP). New classification based on both molecular and classical taxonomy studies is presented including a key to the genera. The subtribe Angraecinae includes 36 genera, 18 of them, included within Angraecum by different authors so far, are treated here. Five new genera are described: Eichlerangraecum, Hermansia, Lesliegraecum, Pectianriella and Rudolfangraecum. Ten sections of Angraecum are raised to the generic status.

Abstract:A new classification of the subtribe Maxillariinae (Orchidaceae) is proposed. Thirty-seven genera are revised. The Camaridium group is divided into seven genera, Adamanthus, Camaridium, Pseudomaxillaria, Psittacoglossum and three described here: Chaseopsis, Chelyella and Viracocha. Ornithidium s.l. is divided into seven genera: Heterotaxis, Laricorchis, Neo-urbania, Nitidobulbon, Ornithidium, Vazquezella and Aucellia, the latter two described here. 193 new combinations on the species level are validated and the relationships among the genera are briefly discussed. A key to the determination of all genera representing Maxillariinae s. s. is provided.

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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.

Current and expected changes in global climate are major threat for biological diversity affecting individuals, communities and ecosystems. However, there is no general trend in the plants response to the climate change. The aim of present study was to evaluate impact of the future climate changes on the distribution of holomycotrophic orchid species using ecological niche modeling approach. Three different scenarios of future climate changes were tested to obtain the most comprehensive insight in the possible habitat loss of 16 holomycotrophic orchids. The extinction of Cephalanthera austiniae was predicted in all analyses. The coverage of suitable niches of Pogoniopsis schenckii will decrease to 1–30% of its current extent. The reduction of at least 50% of climatic niche of Erythrorchis cassythoides and Limodorum abortivum will be observed. In turn, the coverage of suitable niches of Hexalectris spicata, Uleiorchis ulaei and Wullschlaegelia calcarata may be even 16–74 times larger than in the present time. The conducted niche modeling and analysis of the similarity of their climatic tolerance showed instead that the future modification of the coverage of their suitable niches will not be unified and the future climate changes may be not so harmful for holomycotrophic orchids as expected.

The first natural hybrid in the section Irapeana of the orchid genus Cypripedium is described and illustrated based on Guatemalan material. A molecular evaluation of the discovery is provided. Specimens with intermediate flowers between C. irapeanum and C. dickinsonianum within ITS and Xdh sequences have the signal sequence of both these species. The analysis of plastid sequences indicated that the maternal line is C. irapeanum. Information about the ecology, embryology and conservation status of the novelty is given, together with a distribution map of its parental species, C. irapeanum and C. dickinsonianum. A discussion of the hybridization between Cypripedium species is presented. The potential hybrid zones between the representatives of Cypripedium section Irapeana which were estimated based on the results of ecological niche modeling analysis are located in the Maya Highlands (C. dickinsonianum and C. irapeanum) and the eastern part of Southern Sierra Madre (C. molle and C. irapeanum). Moreover, all three Cypripedium species could inhabit Cordillera Neovolcánica according to the obtained models; however, it should be noticed that this region is well-distanced from the edges of the known geographical range of C. molle.