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ABSTRACT A new species of the tribe Malaxideae (Orchidaceae), Crepidium assamicum, is described and illustrated here as new species from Assam, North East India. The new taxon is superficially similar to Crepidium purpureum but differs in its habitat, plant size, long floral bract, very densely flowered inflorescences, leaf number, larger petiole size, both winged throughout and flower color. This species is confined to grow in open grassland near river bank of Dibru‐Soikhowa, Dibrugarh district of Assam, in a huge population comprising 500–600 individuals. The threat status of this new species is provisionally assessed here as “Threatened” following the IUCN Red List Categories and Criteria version 16 (2024). [ABSTRACT FROM AUTHOR]

Background and aims - Bulbophyllum, the largest genus in Orchidaceae, exhibits a diverse morphology in both reproductive and vegetative characters. While trait diversity and evolution has been extensively studied in Malagasy species and within the Cirrhopetalum alliance clade, the evolution of reproductive and vegetative characters at the whole level of the Asian clade remains largely unexplored. Material and methods - We reconstructed the phylogeny of approximately 11% of all Asian Bulbophyllum species using Bayesian inference and maximum likelihood estimation based on nuclear (ITS) and chloroplast (matK, psbA-trnH) DNA sequence data. This phylogenetic framework allowed us to examine the evolution of two vegetative and four floral characters through ancestral state reconstruction. Key results and conclusion - The ancestral character states of the Asian clade of Bulbophyllum include a single leaf, distinct pseudobulbs, multiple-flowered inflorescences, and lateral and dorsal sepals similar in length. One-leaved pseudobulbs evolved into two-leaved pseudobulbs multiple times. Distinct pseudobulbs gave rise to indistinct pseudobulbs twice. Multiple-flowered inflorescences shifted to solitary flowers and 2-3-flowered inflorescences multiple times, with some instances of evolutionary reversal. Lateral sepal elongation also presents a convergent evolutionary scenario. [ABSTRACT FROM AUTHOR]

Epipogium roseum (D.Don) Lindl., an ephemeral, achlorophyllous, mycoheterotrophic, terrestrial orchid is reported as a new state record after its first collection from the Paderu hills of Andhra Pradesh, India. Detailed descriptions, information on the type, ecology, photographs, and details of voucher specimens are provided. [ABSTRACT FROM AUTHOR]

Didymoplexiella, a holomycotrophic terrestrial orchid genus has been reported for the first time in India. In India, the genus is represented by D. siamensis, and has been reported from Sikkim. Detailed morphology, supplemented with illustrative photoplates, along with information on habitat and phenology has been provided. Conservation assessment of D. siamensis has been done following IUCN guidelines. [ABSTRACT FROM AUTHOR]

Bulbophyllum romklaoense (B. sect. Lemniscata) from northern Thailand is described and illustrated as a species new to science. It is most similar to B. muscarirubrum and B. triste, but differs by having inflorescences with only 4–6 reddish-brown flowers, falcatesubovate lateral sepals that are connate only in the upper half along the interior margins, petals with erose to fimbriate margins and a lip with long cilia in the distal half on the lower surface. A comparison with other similar species in the section, as well as notes on ecology, phenology, conservation assessment and a key to B. sect. Lemniscata in Thailand are also provided. [ABSTRACT FROM AUTHOR]

Two new species of Bulbophyllum,B. barcelonae and B. pelseri are described here from the Pantabangan‐Carranglan Watershed Forest Reserve, Luzon Island, Philippines. Bulbophyllum barcelonae resembles B. charisae, but differs by having smaller vegetative parts, ovate petals with a rounded apex, and a labellum with two ridges that are strongly angled outwards the adaxial surface, rounded proximal crests, and a canaliculate abaxial surface. Bulbophyllum pelseri resembles B. aureobrunneum but differs by having caducous sheath covering the pseudobulbs, punctulate leaf surface, shorter leaves, absence of transverse callus in median portion of labellum, median portion with short, rounded ridge, rounded apex, and triangular stelidia. These discoveries increase to 207, the known species of Bulbophyllum in the Philippines. An Abstract in Philipino can be found in the Supporting information. [ABSTRACT FROM AUTHOR]

After a confused taxonomic history, Prosthechea (Laeliinae, Orchidaceae) has been circumscribed in a broad sense to include species previously placed in Encyclia subg. Osmophytum. However, recent alternative classifications resurrecting old names such as Anacheilium and Hormidium, and proposing new genera such as Euchile, Panarica, Pollardia, and Pseudencyclia were presented, splitting Prosthechea into narrower genera. In this study, we provide a molecular phylogeny of Prosthechea to reassess alternative generic classifications and shed light on evolutionary aspects of this highly diverse Neotropical lineage. Eighty species of Prosthechea s.l. and 12 species of related genera were sampled. Bayesian and maximum parsimony analyses of sequences from three plastid regions (rpl32‐trnL, trnD‐trnT, ycf1) and nrITS were included. Possible conflicts between nuclear and plastid data were assessed with partitioned Bremer support. Ancestral state reconstructions of morphological characters relevant to the genus taxonomy are provided. Our results reinforce the monophyly of the lineage corresponding to a broad circumscription of Prosthechea. The small lineages corresponding to Euchile, Panarica, and Hormidium are monophyletic, whereas the larger Anacheilium, Pollardia, and Pseudencyclia are not monophyletic. Splitting Prosthechea into smaller genera is not supported by our phylogeny, and nonmonophyly also hinders the proposal of a comprehensive infrageneric classification. The phylogenetic relationships recovered reflect better the biogeographic patterns than the previously proposed morphological affinities, pointing to the existence of homoplastic floral traits within the genus. Conflicts between nuclear and plastid partitions were detected, suggesting a possible scenario of reticulate evolution. [ABSTRACT FROM AUTHOR]

A new species, Uncifera motuoensis (Orchidaceae: Epidedroideae: Aeridinae) from Xizang Autonomous Region, China is described and illustrated with detailed photos and scientific illustration. Detailed morphological comparisons indicate that U. motouensis is similar to U. obtusifolia, but differs in having entire mid-lobe of lip, narrower leaf blade and wider pollinarium stipe. For the identification, a key to the known seven species of Uncifera is presented. [ABSTRACT FROM AUTHOR]

Background and Aims Epiphytism has evolved repeatedly in plants and has resulted in a considerable number of species with original characteristics. Because water supply is generally erratic compared to that in soils, succulent forms in particular are widespread in epiphytic species. However, succulent organs also exist in terrestrial plants, and the question of the concomitant evolution of epiphytism and succulence has received little attention, not even in the epidendroid orchids, which account for 67.6 % of vascular epiphytes. Methods We built a new time-calibrated phylogenetic tree of Epidendroideae with 203 genera treated in genus Orchidacearum , from which we reconstructed the evolution of epiphytism as well as traits related to water scarcity (stem and leaf succulence and the number of velamen layers), while testing for the correlated evolution between the two. Furthermore, we estimated the ancestral geographical ranges to evaluate the palaeoclimatic context in which epiphytism evolved. Key Results Epiphytism evolved at least three times: 39.0 million years ago (Mya) in the common ancestor of the Malaxideae and Cymbidieae that probably ranged from the Neotropics to Southeast Asia and Australia, 11.5 Mya in the Arethuseae in Southeast Asia and Australia, and 7.1 Mya in the neotropical Sobralieae, and it was notably lost in the Malaxidiinae, Collabieae, Calypsoeae, Bletiinae and Eulophiinae. Stem succulence is inferred to have evolved once, in a terrestrial ancestor at least 4.1 Mya before the emergence of epiphytic lineages. If lost, stem succulence was almost systematically replaced by leaf succulence in epiphytic lineages. Conclusions Epiphytism may have evolved in seasonally dry forests during the Eocene climatic cooling, among stem-succulent terrestrial orchids. Our results suggest that the emergence of stem succulence in early epidendroids was a key innovation in the evolution of epiphytism, facilitating the colonization of epiphytic environments that later led to the greatest diversification of epiphytic orchids. [ABSTRACT FROM AUTHOR]

Microcoelia and the monospecific Taeniorrhiza and Chauliodon are notable among Afrotropical angraecoid orchids for being leafless. However, the affinity among these genera was not addressed in previous molecular phylogenetic studies, thus precluding the understanding of how many times has leaflessness evolved in angraecoids. The discovery of an additional species ascribable to Taeniorrhiza in Gabon, and a revision of all material referrable to this genus in herbarium collections, created the possibility to investigate the phylogenetic position of Taeniorrhiza relative to Microcoelia and Chauliodon. Based on phylogenetic inference using ITS‐1 and two plastid regions (matK/trnK, trnL‐trnF), and including 20 of the 34 species of Microcoelia recognised prior to our study, we here demonstrate that Taeniorrhiza and Chauliodon are deeply imbedded in Microcoelia, and are thus treated here as synonyms of the last. Accordingly, we describe the novelty from Gabon as a new species of Microcoelia: Microcoelia nguemae sp. nov. The new species is illustrated with colour photographs, and also with line drawings. Its preliminarily IUCN conservation status is provided. The novelty is notable for the dorsiventrally asymmetric distribution of pneumathodes along its roots and for bearing the longest lip spur in this Afro‐Malagasy epiphytic genus. The new phylogenetic framework suggests a single origin of leaflessness in Afrotropical angrecoids and reveals the informative value of the rostellum to reconstruct relationships within Microcoelia. This serves as the basis of a newly proposed sectional treatment for Microcoelia, recognising 37 species, one new section, a new status for the defunct genus Encheiridion and the redefinition of Microcoelia sect. Microcoelia and sect. Brachyglossa. [ABSTRACT FROM AUTHOR]

A new orchid species from southern Thailand, Aphyllorchis periactinantha, is described and illustrated. The novelty is characterized by the subactinomophic flowers, the concave labellum, not divided into hypochile and epichile, the reduced staminodes, the shallowly bilobed stigma and the semicircular rostellum. A key to the species of Aphyllorchis in Thailand is updated. [ABSTRACT FROM AUTHOR]

Danxiaorchis mangdangshanensis, a new mycoheterotrophic species from Fujian Province, China, is described and illustrated. The new species is morphologically similar to D. singchiana, but its callus of labellum is a less distinctive Y-shape with three auricles on the apex, four pollinia that are narrowly elliptic in shape and equal in size, and it lacks fine roots. The plastome of D. mangdangshanensis is highly degraded. Phylogenetic analyses distinguished D. mangdangshanensis from its congeners, D. singchiana and D. yangii, with strong support based on nrITS + matK and plastomes, respectively. [ABSTRACT FROM AUTHOR]

Here we study a challenging group of karyotypically highly variable Epidendrum spp. using phylogenetic methods to help understand how hybridization/introgression contributes to karyotype evolution. We hypothesize that species with great chromosome number variation are a result of past hybridization/introgression. Conflicting topologies in trees constructed using separate plastid and nuclear datasets suggest past hybridization events that occurred most probably at least 3.7 Mya. A basic number x = 14 and substantial karyotype change followed by species divergence are suggested. Descending dysploidy and polyploidy were the most frequent changes estimated across the phylogenetic tree of the group. Two species, Epidendrum secundum and E. xanthinum , have probably experienced unidirectional gene flow involving their ancestors (the pollen recipients) and ancestors of E. puniceoluteum and E. denticulatum/E. flammeum , respectively, the pollen donors. However, it is not possible to say whether hybridization participated in the origin of E. secundum and E. xanthinum or merely contributed to their genomic divergence and karyotype change through introgression as has been observed in modern hybrid zones in Epidendrum. This pattern of introgression causing karyotype disruption and divergence could help explain the enigma of some highly diverse genera, such as Epidendrum. Further studies using a wider sampling of the genus could test if gene flow and karyotype variability are associated with the increase of speciation rates. [ABSTRACT FROM AUTHOR]

Premise: Angiosperms distributed over a large geographical area may display considerable phenotypic variation that can be recognized at morphological and micromorphological levels. Here, we investigate the pollination biology and the presence of floral rewards in Brazilian populations of the widely distributed orchid, Brasiliorchis picta. Based on the new data presented here this study investigates the evolution of floral rewards in Maxillariinae, and tests for the occurrence of convergent evolution of food‐hairs in this subtribe. Methods: Micromorphological and histochemical analyses of the labellar tissues were conducted, together with chemical analysis of fragrance and experiments involving the use of chemical baits. The evolution of floral rewards in Maxillariinae were addressed. Results: Microscopy revealed that B. picta offers food‐hairs as a reward. Fragrance is produced by abaxially located labellar epidermal papillae. The main compound present in our samples (2‐phenylethanol) also occurs in the aggregation pheromone produced by the mandible glands of pollinators, Meliponini bees. Our analyses indicate a high diversity of flower rewards and pollinators displayed by members of Maxillariinae, and support that edible trichomes evolved independently five times in the subtribe. Conclusions: The high diversity of floral rewards and pollinators displayed by members of Maxillariinae suggests that different pollinator pressures are involved in the evolution of this neotropical subtribe. In addition, the offering of food‐hairs, which are generally infrequently encountered in Orchidaceae, arose by convergent evolution in Maxillariinae. [ABSTRACT FROM AUTHOR]

A new species of Epidendrum L. from northern Peru is described, illustrated, and compared with related species. This new species belongs to the Laxicaule Group and shares morphological characteristics with Epidendrum laxicaule D.E. Benn & Christenson but differs in the shape and length of the dorsal sepal; the shape of the petals and the lip, ribs position of the lip, shape of the vesicle formed between the ovary and the column as well as the section of the stem. [ABSTRACT FROM AUTHOR]

Orchid seeds have great morphological variations that imply the phylogenetic relationship of the species depending on the biodiversity of the family or act as an adaptation to seed dispersal mechanisms depending on the life form. This study aims to both describe and analyse the qualitative and quantitative traits of 12 Turkish orchids representing epidendroids and orchidoids in detail to investigate which properties are diagnostic among these taxa and also reveal if seed properties are differentiated in relationship to the ecological preferences of the studied species. Both qualitative and quantitative features were determined, and measurements were obtained using light and scanning electron microscopy. We applied the unweighted pair group method with arithmetic mean (UPGMA) cluster analysis and canonical discriminant analysis to the qualitative and quantitative traits. Furthermore, we analyzed the same orchid seed in correlation with ecological traits such as habitats and the elevation preferences of species. This study confirmed the usefulness of both data sets for effectively assessing the variation of orchid seeds. Although the seed characters such as the cell shape differences in the chalazal or medial region, seed sizes, cell numbers on the longitudinal axis, and periclinal wall ornamentation are taxonomically conserved, some other characteristics such as seed shape, the absence of periclinal wall ornamentation, and larger embryo size imply ecological adaptation or developmental achievement for germination. This study confirms the diagnostic value of both qualitative and quantitative seed features, which are effective in explaining the orchid seed variety. [ABSTRACT FROM AUTHOR]

A new Javan endemic Tuberolabium species, Tuberolabium camperenik Yudistira, Naive & Romiyadi, is herein described and illustrated. It is unique among the three Tuberolabium species found in Indonesia by having crystal white flowers and a long, very narrow spur not thickened on the front wall around the epichile. Detailed description, colour plates, phenology, distribution and a preliminary conservation assessment are provided in this paper. [ABSTRACT FROM AUTHOR]

The first complete chloroplast (cp) genome sequences of an endemic and endangered species in China, Calanthe henryi, were reported in this study. The cp genome of C. henryi was 158,256 bp long, with two inverted repeat (IR) regions of 26,348 bp, a large single copy (LSC) region of 87,137 bp, and a small single copy (SSC) region of 18,423 bp. The cp genome of this species contained 113 genes, including 79 protein-coding genes, 4 ribosomal RNA genes, and 30 transfer RNA genes. The overall GC content was 36.7%. Phylogenetic analysis of 60 cp genomes within the subfamily of Epidendroideae suggests that C. henryi is closely related to C. bicolor.

Background and Aims: Heterotrophic plants have long been a challenge for systematists, exemplified by the base of the orchid subfamily Epidendroideae, which contains numerous mycoheterotrophic species., Methods: Here we address the utility of organellar genomes in resolving relationships at the epidendroid base, specifically employing models of heterotachy, or lineage-specific rate variation over time. We further conduct comparative analyses of plastid genome evolution in heterotrophs and structural variation in matK., Key Results: We present the first complete plastid genomes (plastomes) of Wullschlaegelia, the sole genus of the tribe Wullschlaegelieae, revealing a highly reduced genome of 37 kilobases, which retains a fraction of the genes present in related autotrophs. Plastid phylogenomic analyses recovered a strongly supported clade composed exclusively of mycoheterotrophic species with long branches. We further analyzed mitochondrial gene sets, which recovered similar relationships to those in other studies using nuclear data, but the placement of Wullschlaegelia remains uncertain. We conducted comparative plastome analyses among Wullschlaegelia and other heterotrophic orchids, revealing a suite of correlated substitutional and structural changes relative to autotrophic species. Lastly, we investigated evolutionary and structural variation in matK, which is retained in Wullschlaegelia and a few other 'late stage' heterotrophs and found evidence for structural conservation despite rapid substitution rates in both Wullschlaegelia and the leafless Gastrodia., Conclusions: Our analyses reveal the limits of what the plastid genome can tell us on orchid relationships in this part of the tree, even when applying parameter-rich heterotachy models. Our study underscores the need for increased taxon sampling across all three genomes at the epidendroid base, and illustrates the need for further research on addressing heterotachy in phylogenomic analyses., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background: Orchidaceae represents around 7.1-8.52 % of the angiosperms known in the planet. In Mexico, orchids are the third family more diverse, and Oaxaca is the state with the highest richness in the country. Orchids are widely distributed in tropical environments, but they are also distributed in temperate forests, where they have been scarcely studied. Questions: What is the diversity of orchid species at the locality of Santa Catarina Lachatao? Which subfamilies and growth forms are distributed at that locality? Do the community of orchids flowers differentially between seasons? Studied species: Species of the Orchidaceae family. Study site and dates: Santa Catarina Lachatao, Oaxaca, 2017-2018. Methods: Orchids were collected monthly throughout a year. Collected specimens were identified. Richness, abundance and diversity index were estimated for the whole flowering community, and per subfamily and growth form. These parameters were compared between seasons. Results: The community of orchids was composed by 4,933 flowering individuals from 74 species from the subfamilies Epidendroideae and Orchidoideae. Orchids with terrestrial, epiphyte, and rupicolous growth forms were collected. Total diversity index and species composition varied between seasons. Seasonal variation in abundance, diversity and species composition per subfamily and per growth form was also detected. Conclusions: Orchid diversity at the locality is high (9.68 % of the richness recorded for Oaxaca), and varies between seasons. The high species richness, the endemisms and endangered species found, call to take prompt actions to protect and manage the forest to assure its conservation and the diversity within it.

The Neotropical genus Palmorchis (Orchidaceae) contains 38 species distributed from Nicaragua to Peru, including northern Brazil. The genus is characterized by whitish or greenish tubular flowers with morphologically similar sepals and petals, a generally trilobed lip basally adnated to the gynostemium, and a gynostemium with a more or less curved apex. Here, a new species of Palmorchis belonging to the informal Palmorchis sobralioides group is described and illustrated from the state of Pará in the Brazilian Amazon, and its taxonomic affinities are discussed. Palmorchis triquilhada is close to P. sobralioides, differing basically by having a smaller size, pubescent leaves, deltoid and pubescent floral bracts, pubescent lip with ciliate margin, and a three‐keeled lanceolate median lobe without calli and with an acute apex. A description, photos, illustrations and ecological and taxonomic comments are provided for the species, as well as an identification key for related species. [ABSTRACT FROM AUTHOR]

The phylogenetic position of Rangaeris (Schltr.) Summerh. has been one of the most problematic issues of angraecoid orchid taxonomy. A recently published phylogenetic tree with nearly comprehensive taxon sampling of African angraecoid orchids suggested that this genus was polyphyletic, as its species appear nested within different subclades of the Cyrtorchis-Tridactyle clade. However, the lack of DNA data for the generic type, R. muscicola (Rchb. f.) Summerh., and for the little-known species R. longicaudata (Rolfe) Summerh. and R. trilobata Summerh., has precluded an integrative reappraisal of the delimitation of this genus. Here we present the results of a new phylogenetic analysis of one nuclear (ITS) and five plastid markers (matK, rps16, trnC-petN intergenic spacer, trnL-trnF intergenic spacer, ycf1) for all six species of Rangaeris, including those recently transferred to Podangis Schltr. and Ypsilopus Summerh., together with a representative sampling of 14 other species of the genera Cyrtorchis Schltr., Listrostachys Rchb. f., Plectrelminthus Raf., Summerhayesia P. J. Cribb, Tridactyle Schltr., and Ypsilopus. Based on molecular and morphological evidence, R. muscicola is transferred to Podangis, where Rangaeris is reduced to the rank of section. In addition, R. longicaudata and R. trilobata are each moved to new monotypic genera, Planetangis St'evart & Farminhão and Aziza Farminhão & D'haijere, respectively. An identification key for all genera of the Cyrtorchis-Tridactyle clade is presented, together with one for the three species of recircumscribed Podangis. Finally, taxonomic accounts of the new genera are presented, including amended descriptions, illustrations, distribution maps, and preliminary conservation status assessments of their species. [ABSTRACT FROM AUTHOR]

Orchids, differently from most flowering plants, have under-differentiated ovules at anthesis that require pollination to complete differentiation. This ovule developmental stage has been often observed in tropical species in which the absence of an evident seasonality may allow plants to extend their phenology beneficiating of a long time for post-pollination events. Here, we used scanning electron microscopy (SEM) to detect ovule integument developmental stages in 21 species of Mediterranean Orchidoideae and Epidendroideae and in 11 tropical Epidendroideae with the aim of understanding whether species with a seasonal constraint and shorter time for post-pollination ovule maturation are characterized by different stages of ovule development at anthesis. We found that Mediterranean orchids (both Orchidoideae and Epidendroideae) have more developed ovule integuments than tropical orchids. Most species show partially to fully developed ovules at anthesis with the exception of Cephalanthera where ovules are arrested in a very early developmental stage. Despite the phylogenetic signal, anthetic ovule integument development differs between related species (with different pollination strategies or blooming times), suggesting the presence of some ecological constraints. The synchronization between ovule integuments and megagametophyte development, as found in tropical orchids, is also confirmed in Mediterranean orchids. Our data show that Mediterranean and tropical orchids clearly differ in anthetic ovule developmental stages, likely depending on seasonality. [ABSTRACT FROM AUTHOR]

Self-incompatibility affects not only the formation of seeds, but also the evolution of species diversity. A robust understanding of the molecular mechanisms of self-incompatibility is essential for breeding efforts, as well as conservation biology research. In recent years, phenotypic and multiple omics studies have revealed that self-incompatibility in Orchidaceae is mainly concentrated in the subfamily Epidendroideae, and the self-incompatibility phenotypes are diverse, even in the same genus, and hormones (auxin and ethylene), and new male and female determinants might be involved in SI response. This work provides a good foundation for future studies of the evolution and molecular mechanisms of self-incompatibility. We review recent research progress on self-incompatibility in orchids at the morphological, physiological, and molecular levels, provide a general overview of self-incompatibility in orchids, and propose future research directions.

Bulbophyllum disciflorum is one of Orchidaceae species, which has important ornamental and economic value. Here, we reported the first chloroplast genome sequence of Bulbophyllum. The genome of B. disciflorum is 148,554 bp in length, including a large single-copy (LSC) of 79,001 bp, a small single-copy (SSC) of 16,797 bp, and a pair of inverted repeat regions (IRa and IRb) of 26,378bp. It contains 108 unique genes consisting of 74 protein-coding genes, 30 tRNA genes, and 4 rRNA genes. The phylogenetic analysis revealed that Bulbophyllum is sister to the genus of Dendrobium.

The number of integuments found in angiosperm ovules is variable. In orchids, most species show bitegmic ovules, except for some mycoheterotrophic species that show ovules with only one integument. Analysis of ovules and the development of the seed coat provide important information regarding functional aspects such as dispersal and seed germination. This study aimed to analyze the origin and development of the seed coat of the mycoheterotrophic orchid Pogoniopsis schenckii and to compare this development with that of other photosynthetic species of the family. Flowers and fruits at different stages of development were collected, and the usual methodology for performing anatomical studies, scanning microscopy, and transmission microscopy following established protocols. P. schenckii have ategmic ovules, while the other species are bitegmic. No evidence of integument formation at any stage of development was found through anatomical studies. The reduction of integuments found in the ovules could facilitate fertilization in this species. The seeds of P. schenckii, Vanilla planifolia, and V. palmarum have hard seed coats, while the other species have seed coats formed by the testa alone, making them thin and transparent. P. schenckii, in contrast to the other species analyzed, has a seed coat that originates from the nucellar epidermis, while in other species, the seed coat originates from the outer integument.

Colleters are trichomes or emergencies that produce a sticky exudate consisting of a mixture of mucilage, lipids, terpenes, and phenolic compounds. Colleters occur in at least 60 families of angiosperms; however, reports of them are scarce for the Orchidaceae. Elleanthus brasiliensis is distinguished by the presence of an abundant gelatinous secretion that covers almost all of its inflorescences. We aimed to describe the histology of colleters in inflorescences of E. brasiliensis and Elleanthus crinipes, and to analyze the chemical composition of their secretion to better understand the functions of these secretory structures. Due to the low frequency of colleters and lack of visible secretion in E. crinipes, histochemical tests and chemical analyses were not performed for this species. Colleters are of a brush type and their secretion has, at the same time, hydrophilic and lipophilic components. Histochemical tests further revealed the presence of pectin, mucilage, lipids, terpenes, phenolic compounds, and proteins. The GC-MS analysis confirmed the presence of γ-sitosterol and palmitic, linoleic, and stearic acids in the secretion of E. brasiliensis. Infrared analysis indicated the possible presence of polysaccharides in the secretion. The occurrence of colleters in both species studied and in other orchids described in the literature suggests that these structures are common in the inflorescences of tropical orchids. In these environments, the hydrated polysaccharides in the secretion form a dense matrix that can act as a physical barrier, and terpenes may help to protect against herbivores and pathogenic microorganisms. This information broadens our knowledge of the morphological and chemical diversity of the secretions produced by orchid colleters.

Bulbophyllumromklaoense (B.sect.Lemniscata) from northern Thailand is described and illustrated as a species new to science. It is most similar to B.muscarirubrum and B.triste , but differs by having inflorescences with only 4-6 reddish-brown flowers, falcate-subovate lateral sepals that are connate only in the upper half along the interior margins, petals with erose to fimbriate margins and a lip with long cilia in the distal half on the lower surface. A comparison with other similar species in the section, as well as notes on ecology, phenology, conservation assessment and a key to B.sect.Lemniscata in Thailand are also provided., Competing Interests: The authors have declared that no competing interests exist., (Nicha Thawara, Thitiporn Pingyot, Piyakaset Suksathan, Saroj Ruchisansakun.)

Se presenta un catálogo actualizado de las especies y táxones infraespecíficos de la familia Orchidaceae en Guinea Ecuatorial, obtenido a partir de testimonios de herbario y revisión bibliográfica. Nuestros resultados indican la presencia de 225 táxones más 12 que requieren confirmación en el conjunto del territorio (Annobón, Bioko y Río Muni), incluidos en 43 géneros y 10 tribus pertenecientes a las subfamilias Vanilloideae, Orchidoideae y Epidendroideae. Se aportan 88 táxones más en el catálogo de Río Muni respecto a publicaciones precedentes. La tribu Vandeae es la más representada, con 118 táxones. Atendiendo al hábito, 53 táxones son terrestres, seis son trepadores y 166 son epífitos. La mayor riqueza de orquídeas se manifiesta en la isla de Bioko y en las provincias occidentales de Río Muni. De las 31 especies descritas sobre materiales ecuatoguineanos, seis son consideradas endemismos de Guinea Ecuatorial.

The number of integuments found in angiosperm ovules is variable. In orchids, most species show bitegmic ovules, except for some mycoheterotrophic species that show ovules with only one integument. Analysis of ovules and the development of the seed coat provide important information regarding functional aspects such as dispersal and seed germination. This study aimed to analyze the origin and development of the seed coat of the mycoheterotrophic orchid Pogoniopsis schenckii and to compare this development with that of other photosynthetic species of the family. Flowers and fruits at different stages of development were collected, and the usual methodology for performing anatomical studies, scanning microscopy, and transmission microscopy following established protocols. P. schenckii have ategmic ovules, while the other species are bitegmic. No evidence of integument formation at any stage of development was found through anatomical studies. The reduction of integuments found in the ovules could facilitate fertilization in this species. The seeds of P. schenckii , Vanilla planifolia , and V. palmarum have hard seed coats, while the other species have seed coats formed by the testa alone, making them thin and transparent. P. schenckii, in contrast to the other species analyzed, has a seed coat that originates from the nucellar epidermis, while in other species, the seed coat originates from the outer integument. [ABSTRACT FROM AUTHOR]

Previous phylogenetic analyses focused on angraecoid orchids suggested that the genus Ypsilopus was paraphyletic and that some species of Tridactyle and Rangaeris belong to a clade that included Ypsilopus. These studies, based on three to four genes, sampled few taxa in each genus, and did not include the type of Rangaeris, nor did they take morphological variation into account. To delineate Ypsilopus more precisely, we reconstructed phylogenetic relationships of the genus and seven other closely related genera by analysing sequence variation at the nuclear ribosomal internal transcribed spacer (ITS‐1) and at five plastid markers (matK, rps16, trnC‐petN intergenic spacer, trnL‐trnF intergenic spacer, ycf1), from 42 specimens representing 36 taxa. Trees based on maximum likelihood and Bayesian inference confirm that two species of Tridactyle are nested with three Ypsilopus species, including the type of the latter, and two species of Rangaeris are grouped with this clade. Moreover, we examined morphological variation among all species belonging to these three genera, highlighting morphological features that characterize Ypsilopus, and we used these data to assign the two species of Tridactyle included in the molecular analyses, three other species of Tridactyle not included in the molecular analyses and two species of Rangaeris to Ypsilopus. New combinations for Tridactyle citrina, T. furcistipes, T. sarcodantha, T. tanneri, T. tricuspis, Rangaeris amaniensis and R. schliebenii in Ypsilopus are thus proposed, and one new section (i.e., Ypsilopus sect. Barombiella) is described. Keys to the species of Ypsilopus and closely related genera are provided, along with a table of characters that can be used to differentiate these species. [ABSTRACT FROM AUTHOR]

In this research, anatomical, leaf micromorphological features of the samples belonging to 25 taxa (Anacamptis Rich., Cephalanthera Rich., Dactylorhiza Necker ex Nevski, Gymnadenia R.Br., Himantoglossum Spreng., Limodorum Boehm., Ophrys L., Orchis L., Platanthera Rich., Serapias L., Spiranthes Rich. and Steveniella Schltr.) spread in the Karadeniz Region have been evaluated comparatively. In anatomical studies, the transverse section from root, stem and leaf, and surface section from leaves of plants were examined. In addition, micromorphological properties of leaf were determined by electron microscopy. Morphometrical analyses were carried out using the anatomical and leaf micromophological characters of each taxa. The data matrices were obtained by examining the results of at least three samples collected from different localities. The data were evaluated using Statistical Package for the Social Sciences (SPSS) and PAleontological STatistics (PAST) statistical programs with PCA, linear discriminant analysis (LDA), and unweighted pair group method with arithmetic mean analysis. Anatomical characteristics of plants such as root epidermis cell length, cortex diameter and pith cell diameter, leaf upper epidermis length–width and bulliform cell length–width were determined to be important characteristics. It was concluded that these characters are especially important in grouping at the genus level. [ABSTRACT FROM AUTHOR]

We studied the variation in the pollinarium and pistil of Epidendroideae and reconstructed the ancestral states of the characters (pollinia number, pollinium orientation, pollinium with suture, and pollinium texture). The pollinarium is complete (formed by pollinium, caudicle, stipe, and viscidium) in Vandeae, Epidendreae, and Cymbidieae, but the caudicle is absent in some Aeridinae and the viscidium in Laeliinae and Pleurothallidinae. Neottieae, Arethuseae, Sobralieae, Epidendreae, and Xerorchideae included some genera having sessile pollinia. The more frequent state in the family is to have two pollinia, followed by four, eight, and six pollinia. The pistil is unilocular, although it seems to have experienced reversals several times within Epidendroideae because intermediate states were observed (e.g. Vanda and Angraecum). In these cases, a prolongation of the placental tissue is developed that in Huntleya and Peristeria make contact but do not fuse. Most members of the subfamily have pistil composed of three carpels divided into six emerging valves, but only three are fertile. In Cattleya and Sophronitis the sterile valves are much reduced and the pistil seems to have only three valves. We have generated useful and valuable information to understand the evolution of the reproductive organs in Epidendroideae. Probably, these transformations in the pollinarium and pistil have co-evolved in tandem with pollinators to make the pollination more efficient. Our results suggest that the common ancestor of Epidendroideae had a complete pollinarium, formed probably of four juxtaposed granular pollinia without suture, bearing caudicle, tegular stipe and viscidium, but several early transformations occurred during the Epidendroideae diversification. [ABSTRACT FROM AUTHOR]

Colleters are trichomes or emergencies that produce a sticky exudate consisting of a mixture of mucilage, lipids, terpenes, and phenolic compounds. Colleters occur in at least 60 families of angiosperms; however, reports of them are scarce for the Orchidaceae. Elleanthus brasiliensis is distinguished by the presence of an abundant gelatinous secretion that covers almost all of its inflorescences. We aimed to describe the histology of colleters in inflorescences of E. brasiliensis and Elleanthus crinipes , and to analyze the chemical composition of their secretion to better understand the functions of these secretory structures. Due to the low frequency of colleters and lack of visible secretion in E. crinipes , histochemical tests and chemical analyses were not performed for this species. Colleters are of a brush type and their secretion has, at the same time, hydrophilic and lipophilic components. Histochemical tests further revealed the presence of pectin, mucilage, lipids, terpenes, phenolic compounds, and proteins. The GC-MS analysis confirmed the presence of γ-sitosterol and palmitic, linoleic, and stearic acids in the secretion of E. brasiliensis. Infrared analysis indicated the possible presence of polysaccharides in the secretion. The occurrence of colleters in both species studied and in other orchids described in the literature suggests that these structures are common in the inflorescences of tropical orchids. In these environments, the hydrated polysaccharides in the secretion form a dense matrix that can act as a physical barrier, and terpenes may help to protect against herbivores and pathogenic microorganisms. This information broadens our knowledge of the morphological and chemical diversity of the secretions produced by orchid colleters. [ABSTRACT FROM AUTHOR]

Here we review the taxonomy of the species included in Campylocentrum sect. Laevigatum, which are characterized by smooth roots, conduplicate leaves, and unribbed capsules. Fourteen species are recognized; eleven of them are endemic to Brazil, two occur in Argentina, Brazil, Paraguay, and Uruguay, and one (C. jamaicense) is endemic to the Antilles. According to the IUCN criteria, Campylocentrum brevifolium and C. pauloense are classified as Critically Endangered and Vulnerable, respectively. We provide typifications for 10 names, complete synonymies, conservation statuses, descriptions, and an identification key to the species. [ABSTRACT FROM AUTHOR]

Highlights • In Brazil, the flowers of Ionopsis utricularioides are nectarless. • Its flowers are pollinated by several bee species. • Brazilian populations of this orchid are self-incompatible. • The orchid flowers have similar colours to many other co-flowering species. • These results are consistent with non-specific deceptive pollination. Abstract Oncidiinae is one of the largest and most diverse subtribes within Orchidaceae, and many species of this group are known for relying on deceptive pollination through Batesian floral mimicry. Ionopsis utricularioides is a widespread Oncidiinae orchid that occurs from tropical South America to Florida, USA. The pollinators of this species are still unknown, but a previous study in Puerto Rico showed that the species is rewardless and self-compatible. Here we investigate the pollination biology of I. utricularioides in Brazil. To determine if this species is a Batesian mimic we specifically take into account the flower colour of this species and the co-flowering plants in the community. The breeding system experiments revealed that Brazilian populations of I. utricularioides are completely self-incompatible and produces less fruits than those from Puerto Rico under natural conditions. The flowers of I. utricularioides are also nectarless in Brazil and are pollinated by several bee species. The pollinarium is attached on the dorsal portion of the proboscis, while the pollinators put their head inside the flowers searching for nectar. Given that the flower colour is common to several other co-flowering species of the community, our results suggest that this orchid does not represent a case of Batesian mimicry, since it does not mimic a specific model. [ABSTRACT FROM AUTHOR]

Abstract Among the studies on Orchidaceae in the Amazon, none comprised the region of the Great Curve of the Xingu River, located in the lower Xingu river. The aim of this study was to inventory and taxonomically study the species of Oncidiinae (Orchidaceae) in the Great Curve of the Xingu River, Pará state. The floristic survey was performed in the area of the Belo Monte hydroelectric plant, in the Vitória do Xingu municipality, centrally inserted in the called Great Curve of the Xingu River. Botanical collections were accomplished between June 2011 and December 2013. A total of 27 species of Oncidiinae, distributed in 15 genera, was inventoried in the study area. Notylia Lindl. and Trichocentrum Poepp. & Endl. were the richest genera, with five and four species, respectively, followed by Erycina Lindl., Ionopsis Kunth, Lockhartia Hook., Macradenia R.Br., and Ornithocephalus Hook., with two species each. The remaining eight genera are represented by a single species each in the study area. Morphological descriptions, a key for taxonomic identification, illustrations, and comments on distribution, ecology, phenology and morphology are provided for all inventoried species.

Despite significant progress made in recent years toward developing an infrafamilial classification of Orchidaceae, our understanding of relationships among and within tribal and subtribal groups of epidendroid orchids remains incomplete. To reassess generic delimitation among one group of these epidendroids, the African angraecoids, phylogenetic relationships were inferred from DNA sequence data from three regions, ITS, matK, and the trnL-trnF intergenic spacer, obtained from a broadly representative sample of taxa. Parsimony and Bayesian analyses yielded highly resolved trees that are in clear agreement and show significant support for many key clades within subtribe Angraecinae s.l. Angraecoid orchids comprise two well-supported clades: an African/American group and an Indian Ocean group. Molecular results also support many previously proposed relationships among genera, but also reveal some unexpected relationships. The genera Aerangis , Ancistrorhynchus, Bolusiella , Campylocentrum , Cyrtorchis , Dendrophylax, Eurychone , Microcoelia , Nephrangis , Podangis and Solenangis are all shown to be monophyletic, but Angraecopsis, Diaphananthe and Margelliantha are polyphyletic. Diaphananthe forms three well-supported clades, one of which might represent a new genus, and Rhipidoglossum is paraphyletic with respect to Cribbia and Rhaesteria , and also includes taxa currently assigned to Margelliantha . Tridactyle too is paraphyletic as Eggelingia is embedded within it. The large genus Angraecum is confirmed to be polyphyletic and several groups will have to be recognized as separate genera, including sections Dolabrifolia and Hadrangis . The recently segregated genus Pectinariella (previously recognized as A. sect. Pectinaria ) is polyphyletic and its Continental African species will have to be removed. Similarly, some of the species recently transferred to Angraecoides that were previously placed in Angraecum sects. Afrangraecum and Conchoglossum will have to be moved and described as a new genus. [ABSTRACT FROM AUTHOR]

A new Oberonia species, O. muthikulamensis (Orchidaceae), is described and illustrated from Muthikulam forest, Western Ghats of Kerala, India. It is compared with a closely morphologically similar species, O. sebastiana, endemic to Western Ghats. [ABSTRACT FROM AUTHOR]