Characters evolution of Encyclia (Laeliinae-Orchidaceae) reveals a complex pattern not phylogenetically determined: insights from macro- and micromorphology.

Encyclia is the second-largest genus in the neotropical subtribe Laeliinae (Orchidaceae) and has more than 150 species, which are characterized by fairly consistent flower morphology. Its taxonomy and species boundaries, however, seem to be still under debate. In the present study, we first examined the lip micromorphology of 61 species of Encyclia sensu stricto. We correlated our results with external flower morphology and phylogenetic analyses performed on a combined dataset that included both nuclear (ITS, Xdh, PhyC) and plastid markers (ycf1, rpl32, and trnL-trnF). Phylogenetic reconstruction showed that Encyclia sensu stricto species form a coherent, monophyletic group. However, it is difficult to determine the relationships between the different groups within one larger clade. The groups all form distinct lineages that evolved from a common ancestor. The UPGMA cluster analysis for the seven qualitative micromorphological features clearly divides the genus into two main groups, the larger of which is further subdivided into two subgroups. None of these, however, overlap with any of the phylogeographic units distinguished in previously published papers or in presented article. It is worth noting that the groups resulting from the UPGMA analysis cannot be defined by macromorphological features. The pattern of similarities between species, taking into account both macro- and micromorphological features, is eminently mosaic in nature, and only a multifaceted approach can explain this enigmatic group.

Notes to the Taxonomic Affiliation of the Bulbophyllym Sect. Physometra (Orchidaceae, Epidendroideae) Based on Molecular Phylogenetic Analyses.

To solve the taxonomic affiliation of Bulbophyllum physometrum, the only known species of the Bulbophyllym sect. Physometra (Orchidaceae, Epidendroideae), we conducted phylogenetic analyses based on nuclear markers, i.e., ITS and the low-copy gene Xdh, and the plastid region matK. We used Asian Bulbophyllum taxa, with a special focus on species from the sections Lemniscata and Blepharistes, i.e., the only Asian sections of this genus with bifoliate pseudobulbs, as in B. physometrum. Unexpectedly, the results of molecular phylogenetic analyses showed that B. physometrum is most probably more related to the representatives of the sections Hirtula and Sestochilos than Blepharistes or Lemniscata.

Schiedeella bajaverapacensis (Orchidaceae, Spiranthinae), a New Orchid Species from Guatemala.

Guatemala is recognized for its diverse and rich flora and fauna. It is estimated that over 1200 orchid species, classified in 223 genera, are known to occur in this rather small, yet megadiverse country. While studying the diversity of this plant group in the department of Baja Verapaz, we found individuals that clearly belonged to the genus Schiedeella, but whose features did not fit any previously known species. At that time, nine terrestrial taxon representatives were known to occur in Guatemala. We conducted the morphological analysis in accordance with the standard procedures of classical taxonomy. For phylogenetic reconstruction, 59 sequences of the ITS region and 48 of the trnL-trnF marker were applied. The topology of trees was obtained based on the Bayesian inference. Schiedeella bajaverapacensis was described and illustrated based on morphological evidence, and its taxonomic position was confirmed by phylogenetic analyses. The new entity is the 10th Schiedeella representative known from Guatemala.

Floral attractants in the black orchid Brasiliorchis schunkeana (Orchidaceae, Maxillariinae): clues for presumed sapromyophily and potential antimicrobial activity.

BACKGROUND: Orchids have evolved various strategies that aim to ensure their reproduction success. These may include the production of rewards for pollinators, or on the contrary, deception. Specific sets of features such as flower morphology, color, nectar, and odor presence (or lack thereof) are considered to determine suitability for pollination by different groups of animals. Stingless bees are thought to be the primary pollinators of the orchids of the Neotropical subtribe Maxillariinae. However, almost black flowered Brasiliorchis schunkeana at first glance presents floral adaptations that may suggest another pollination syndrome-sapromyophily. RESULTS: A few traces of secretion were noticed on the glabrous lip callus and lip apex built by conical to villiform papillae (SEM analysis). Histochemical studies revealed huge amounts of lipids in the epidermis, subepidermis, and some parenchyma cells (SBB test) with various stages of lipids accumulation between cells. Further TEM analysis showed a heterogeneous (lipoid and phenolic) nature of secretion. The dense osmiophilic cytoplasm contained organelles (RER, free ribosomes, dictyosomes, plastids with plastoglobuli, nucleus) and vesicles migrating to plasmalemma. The vesicles, osmiophilic globules, and flocculent material were visible in periplasmic space. The central vacuole possessed osmiophilic phenolic content and flocculent material. GC-MS analysis revealed in floral extract the presence of 7,9-di-tert-butyl-1-oxaspiro(4,5)deca-6,9-diene-2,8-dione (77.06%) and 2,5-di-tert-butyl-1,4-benzoquinone (16.65%). Both compounds are known for their biological activity. CONCLUSIONS: The juxtaposition of results led us to the conclusion that the labellar tissue produces lipoid and phenolic material, which is responsible for the glossiness and rotten herring scent. This type of secretion could be classified as a phenolic resin. The chemical analysis revealed the presence of five semiochemicals that are known to be attractants for some Diptera, which together with the rest of the results constitutes a strong premise that representatives of this order could be potential pollinators of B. schunkeana. Field observations however are still needed to confirm this pollination syndrome.

Micromorphology of Labellum in Selected Dendrobium Sw. (Orchidaceae, Dendrobieae).

Dendrobium is one of the most species-rich genera of the Paleotropical orchids. It embraces more than 1000 species, most of which are epiphytes. The strong variation in floral characters causes many identification difficulties within this genus. One of the key structures, often sufficient in identification on a species level, is the labellum, which in many species of Dendrobium possesses a thickened callus and various types of trichomes and papillae. The aim of this study is to identify and describe the structures present on the labellum surface of the analyzed species, determine their distribution and density, as well as to check whether the obtained data have taxonomic value. In this paper, we present the results of a micromorphological study on the labellum of 21 species of Dendrobium, representing 13 sections, using scanning electron microscopy (SEM). Our studies revealed the presence of both uni- and multicellular structures on the surface of the labellum. We observed three types of trichomes (conical, cylindrical, ellipsoidal) and three types of papillae (conical, cylindrical, semicircular). Neither trichomes nor papillae were recorded for five species. In addition, we made diagrams showing the distribution and density of structures on the labellum. Based on the micromorphological results combined with the phylogenetic tree performed, we suggest that the presence/absence of labellum structures does not necessarily reflect the phylogenetic relationship and might be misleading, as in some cases, they arise due to convergence.

Maxillariaanacatalinaportillae (Orchidaceae, Maxillariinae), a new remarkable species from Ecuador.

Neotropical genus Maxillaria Ruiz & Pav. belongs to one of the most diverse and species-rich groups of orchids. Several of its representatives are popular, horticultural plants with large and showy flowers, often nicely fragranced. It is not uncommon that some distinctly colored individuals are introduced to the commercial market under names of similar, more or less related species, as informal varieties or color forms, largely causing confusion. While investigating the diversity of Maxillaria in Ecuador, we have encountered plants that were commercially referred to as M.sanderianaxanthina. In the course of conducted morphological and micromorphological analyses, we concluded that it is a new, separate species and hereby, we describe it as M.anacatalinaportillae.

Ornithophily in the subtribe Maxillariinae (Orchidaceae) proven with a case study of Ornithidium fulgens in Guatemala.

Ornithophily has been long speculated to occur in the subtribe Maxillariinae (Orchidaceae), relying either solely on micromorphological analyses or scarce field observations of undefined species. In Guatemala we were able to observe regular visits of the azure-crowned hummingbirds feeding on flowers of Ornithidium fulgens. These observations have led us to investigation of floral attractants by means of scanning and transmission microscopy, histochemical and chemical analyses (GC-MS). Conducted investigation revealed that the epidermis of basal protuberance of column-foot has features proving the secretory activity and that secreted nectar is sucrose-dominant. Slight secretion on the middle part of the lip is puzzling. The presence of other potential pollinators has not been reported. Based on the results of this study, we confirmed that the flowers of O. fulgens meet all criteria of ornithophily and thus that the hypothesis about bird pollination in the subtribe Maxillariinae is proven. The presented results confirm that the previously described floral features predicting the bird pollination in this group are justified. This strengthens the theory about floral adaptations to different pollinators and gives valid reasons to consider species with flowers with a certain set of traits as ornithophilous, even in the absence of the pollination observation.

Species Phylogeny versus Gene Trees: A Case Study of an Incongruent Data Matrix Based on Paphiopedilum Pfitz. (Orchidaceae).

The phylogeny of the genus Paphiopedilum based on the plastome is consistent with morphological analysis. However, to date, none of the analyzed nuclear markers has confirmed this. Topology incongruence among the trees of different nuclear markers concerns entire sections of the subgenus Paphiopedilum. The low-copy nuclear protein-coding gene PHYC was obtained for 22 species representing all sections and subgenera of Paphiopedilum. The nuclear-based phylogeny is supported by morphological characteristics and plastid data analysis. We assumed that an incongruence in nuclear gene trees is caused by ancestral homoploid hybridization. We present a model for inferring the phylogeny of the species despite the incongruence of the different tree topologies. Our analysis, based on six low-copy nuclear genes, is congruent with plastome phylogeny and has been confirmed by phylogenetic network analysis.

Lectotypification of six names in the genus Elleanthus (Orchidaceae) described from J. J. Linden's collection.

The lectotypification of six names of species, originally described as Evelyna Lind. (Orchidaceae), based on collections of Jean Jules Linden from locations that are currently in Venezuela and Colombia, is proposed. We also provide the number and location of duplicates of the type material.

Synopsis of Habenaria s.l. (Orchidaceae) in New Guinea and adjacent islands.

A taxonomic synopsis of the orchid genus Habenaria in New Guinea and adjacent islands is presented. We confirmed the occurrence of 27 Habenaria species in study area. Sixteen of these are endemic and were not so far found outside New Guinea. Morphological characteristics and illustrations of floral segments of taxa are presented. One new species of Habenaria is described. Four neotypes are selected. An updated key to species groups and species occurring in the study area is provided. The importance of diagnostic floral characters in Habenaria is discussed.

Synopsis of Ecuadorian Pterichis (Orchidaceae).

A taxonomic synopsis of the orchid genus Pterichis in Ecuador is presented. All national representatives of this genus are characterized and their floral segments are illustrated. Four new species and two new varieties are described. An updated key to Ecuadorian Pterichis is provided. Plants of the genus are growing mostly as terrestrial herbs at the altitude of 2,300-4,110 m. Often two or more species co-occur in the area of 25 × 25 km. Their occurrence was reported from three ecoregions-the Eastern Cordillera real montane forests, the Northern Andean páramo and the Northwestern Andean montane forests. Seven Ecuadorian Pterichis are endemic.

Towards a taxonomic revision of the genus Cyrtochilum (Orchidaceae) in Northwestern South America (Northern Peru, Ecuador, Colombia, Venezuela).

This article is a presentation of taxonomic diversity of the orchid genus Cyrtochilum in Northwestern South America. The morphological characteristics of over 90 species occurring in northern Peru, Ecuador, Colombia and Venezuela are presented together with illustrations of their floral segments. Information about the distribution of each taxon is provided. Ten morphologically consistent groups have been delineated to facilitate identification of Cyrtochilum representatives in the studied area. Keys for determination of species within each group are provided. Seven new species of Cyrtochilum are described and one new combination is proposed.

Taxonomic revision of the genus Cranichis (Orchidaceae, Cranichideae) in Colombia.

The geographical range of the orchid genus Cranichis extends from USA, Central America, and the Caribbean to Bolivia and Argentina-with the greatest diversity observed in the Andean region. This taxon embraces herbs with the scape and basal leaves developing from a single, terminal bud and having the scape enclosed in several sheaths. The small, non-resupinate, flowers are arranged in a racemose inflorescence. The petals and lip are free from the column part and their gynostemium is short and massive. In this paper, the synopsis of Cranichis in Colombia is presented. Each species occurring in the country is characterized and illustrated. The information about habitat and distribution of national genus representatives are provided. Several groups of species that are very similar in their morphology are delineated to facilitate process of species identification. A total of 10 species are described here as new. Lectotypes for the six species Cranichis ciliata, C. fendleri, C. mandonii, C. tenuis, C. viereckii, and C. wageneri have been selected. Additionally, two new nomenclatorial combinations within Ocampoa are proposed.

Synopsis of the genus Ponthieva (Orchidaceae) in Colombia.

The Neotropical orchid genus Ponthieva R. Br. was established in 1813. The 70 representatives of this taxon are terrestrial, lithophytic, or epiphytic plants with basal, sessile, or petiolate leaves which are glabrous or pubescent. Their erect peduncle is pubescent and terminated by lax, few- to many-flowered raceme. Flowers are non-resupinate, with dissimilar sepals and asymmetrical petals which are adnate to the sides of the gynostemium. The lip is uppermost, fused to the lower part of the gynostemium. Here the synopsis of Colombian Ponthieva is presented. A list of national genus representatives includes 26 species, including one new species, P. vallecaucana Szlach. Kolan. & Oledrzynska, sp. nov., discovered during this study. We did not confirm occurrence of four species reported in previous research. To facilitate process of identification of genus representatives, we divided Ponthieva into six morphological complexes based on vegetative and floral characters. The highest number of species was found in Magdalena and Cauca Valley montane forests. Lectotypes for Ponthieva inaudita and P. mandonii are designated. Morphological characteristics and illustrations of perianth segments of Colombian representatives of the genus are provided as well as a key for their identification.

Global warming not so harmful for all plants - response of holomycotrophic orchid species for the future climate change.

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.

Taxonomy of Cyrtochilum-alliance (Orchidaceae) in the light of molecular and morphological data.

BACKGROUND: The 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. RESULTS: Comparative 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. CONCLUSIONS: A 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.

First Guatemalan record of natural hybridisation between Neotropical species of the Lady's Slipper orchid (Orchidaceae, Cypripedioideae).

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.

Telipogon diabolicus (Orchidaceae, Oncidiinae), a new species from southern Colombia.

A new species of the orchid genus Telipogon, Telipogon diabolicus, is described and illustrated. The information about its habitat is provided. The novelty resembles Telipogon tabanensis and Telipogon guacamayensis and it is characterized by the translucent flowers, the glabrous, distinctly clawed petals, the transversely elliptic lip, and the gynostemium ornamented with long setose hairs on both sides and shorter hairs at the apex.

Phylogenetic placement and taxonomy of the genus Hederorkis (Orchidaceae).

Three plastid regions, matK, rpl32-trnL and rpl16 intron and the ITS1-5.8S-ITS2 nuclear ribosomal DNA were used to demonstrate a phylogenetic placement of the genus Hederorkis (Orchidaceae) for the first time. The taxonomic position of this genus has been unclear thus far. The phylogenetic and morphological relations of Hederorkis to the most closely related genera Sirhookera, Adrorhizon, Bromheadia and Polystachya are also discussed. A hypothesis concerning an origin and evolution of Hederorkis is proposed. Hederorkis is an epiphytic two-leaved orchid genus with lateral inflorescence, non-resupinate flowers, elongate gynostemium and rudimentary column foot. It is native to the Indian Ocean Islands. Two species of Hederorkis are recognized worldwide, H. scandens endemic to Mauritius and Réunion and H. seychellensis endemic to Seychelles. For each of the species treated a full synonymy, detailed description and illustration are included. The distribution map and dichotomous keys to the species have also been provided.

Taxonomic position and phylogeny of the genus Vargasiella (Orchidaceae, Vandoideae) based on molecular and morphological evidence.

Since the description of the Neotropical genus Vargasiella in 1952, its taxonomic position has remained unclear, mainly due to a lack of sufficient data. In this study, the taxonomic position of Vargasiella was revised based on the outcomes of macro- and micromorphological studies, analyses of selected molecular markers and ecological methods of niche distribution modeling. The phylogenetic relationships were inferred using three DNA markers: matK, trnL-F and ITS sequences. The morphological studies included the analysis of macromorphological features of herbarium specimens as well as micromorphological examination of preserved flowers. The ecological niche modeling was applied to identify the distribution of the suitable niches of the studied taxa. The relationships between Vargasiella and most similar taxa remain unresolved based on the molecular analysis. The outcomes from the morphological studies indicated significant differences between Vargasiella, Warrea and Warreopsis. Moreover, a niche shift in response to changing climate after the last glacial maximum is observed in Vargasiella, while no substantial changes in the occupied habitats were identified in the other related taxa. The clocktree of the Zygopetaleae estimated from the matK gene indicated that the most recent common ancestors of Vargasiella, Warrea and Warreopsis originated in the Miocene, while the divergence time for Vargasiella and Warrea was assessed at approximately 5.4 Ma ago. Vargasiella seems to be an outshoot of the main branch of evolution of the Zygopetaleae. It is noteworthy that the Vargasiella-Warrea dichotomy could have taken place later than the divergence of Warreopsis from the mutual lineage. The molecular analysis and morphological data suggest that Vargasiella and Warrea could have evolved from a common ancestor. Accumulation of morphological differences and acceleration of the evolution of Vargasiella were more intensive than in other Warreinae and this could probably be synchronized with adaptation to different climatic conditions.