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Background and aims – Brazil has more than 40 species of Vanilla. Some taxa have been considered to be obscure since they are known only from the type specimen. This is the case of some south-eastern Brazilian species such as V. dubia and V. dungsii. While studying the diversity of Brazilian Vanilla, plants of an unidentified species were found in Ubatuba, São Paulo, Brazil. After flowering, it was confirmed that the species corresponded to the obscure V. dubia. Material and methods – A redescription of V. dubia is provided and a morphological comparison with the related taxa V. dungsii and V. paulista is presented. An illustration of V. dubia is provided, and its geographic distribution is presented. The identity of the enigmatic V. dungsii is also clarified based on holotype examination and on images of living specimens. Key results – Vanilla dubia is recognized by its coriaceous leaves with prominent vascular bundles in transverse section, by its white 3-lobed labellum with yellow lobes and undulate-crenulate margins, and by its tuberculate appendages on the apical portion of the labellar crest. Morphological characteristics suggest a close relationship of V. dubia with V. dungsii and V. paulista. Vanilla dubia occurs in the Dense Ombrophilous Forest, while V. paulista occurs in the Semi-deciduous Mesophytic Forest, and V. dungsii is endemic to the Dense Montane Ombrophilous Forest. Based on current data, V. dubia is assessed as Endangered. Conclusion – Evaluation of vegetative and reproductive characters from living and herbaria specimens is crucial to understanding the identity and species boundaries of Vanilla. The data presented here show that the species occurring in the Atlantic Forest, V. dubia and V. dungsii, are more closely related to each other than to V. paulista, which occurs in Semi-deciduous Mesophytic Forests. A proposal to change the status of V. dungsii as a subspecies of V. dubia can be further considered. [ABSTRACT FROM AUTHOR]

Background and aims -- With 40 species, Brazil is the centre of diversity for Vanilla. Frederico Carlos Hoehne described eight Vanilla species for the Brazilian flora, including Vanilla schwackeana, an obscure taxon currently assumed to be a synonym of V. planifolia. While studying Neotropical Vanilla, plants were found in gallery forests of the Vale do Rio Doce region, Minas Gerais, south-eastern Brazil. Based on the examination of the protologues of the Brazilian species, in addition to the study of herbarium specimens, it was verified that the plants correspond to the rare V. schwackeana. Material and methods -- A redescription of V. schwackeana is provided, and a morphological comparison with other Neotropical taxa is presented. An illustration of V. schwackeana based on living specimens is provided, and its geographic distribution is presented based on recent findings. The position of V. schwackeana within Vanilla is discussed based on both morphological data and a molecular phylogeny. Key results -- Vanilla schwackeana is distinguishable by its pseudopetiolate leaves, by its largely elliptic to obelliptic leaf blades with attenuate base and acuminate apex, by its apical racemes with small flowers, by its yellow labellum with white undulate-crenulate margins, and by its papillous appendages on the apical portion of the labellar crest. Both morphological and molecular data suggest a close relationship of V. schwackeana with V. appendiculata, V. hartii, and the Brazilian endemic V. rupicola. Based on current data, V. schwackeana is assessed as Critically Endangered. Conclusion -- Integrative taxonomy was crucial to understand the identity and species boundaries of V. schwackeana. The V. appendiculata/V. schwackeana/(V. hartii/V. rupicola) clade comprises an unrecognized infrageneric Vanilla group. It seems plausible that the formation of a new infrageneric group will be necessary. As the habitat of V. schwackeana has been devastated by iron ore extraction, conservation strategies for this Brazilian endemic species will be necessary. [ABSTRACT FROM AUTHOR]

Cleistes rosea and 10 other taxa comprise a complex widely distributed in various open vegetation types from eastern South America to Panama. The taxonomic identity of most of these taxa is unclear and their relationships with C. rosea have never been satisfactorily discussed or tested. Here, we employ molecular phylogenetics, morphometrics and morphological, ecological and geographic distribution data to investigate the relationships and taxonomy of Cleistes rosea and related species. Our results confirm that Cleistes rosea and Cleistes castaneoides are sister species and although highly similar in general floral morphology, they differ in vegetative characters, distribution, habitat, floral scent, and lip characters. Both species show local variations regarding floral characters, particularly the flower colour, and such differences were used here to delimit infraspecific taxa within the C. rosea/C. castaneoides clade. While C. rosea var. guianensis var. nov. is restricted to French Guiana, and C. rosea var. buenaventurae stat. & comb. nov. is restricted to low altitudes on the western side of the Cordillera Occidental in the Chocó region of Colombia, C. castaneoides var. castaneoides and C. castaneoides var. augusta comb. nov. are sympatric throughout their distribution. Cleistes abdita, formerly known as C. rosea f. pallida, is similar to C. castaneoides but distinguished by the smaller flowers and restricted distribution to Amazonian savannas. Cleistes rosea is distributed throughout the north of the Andes and northern South America. In turn, C. castaneoides occurs mainly in South-eastern and Central-western Brazil. Still, the distribution of these three species overlaps in the Guiana Shield, where the differentiation between them is less evident. Our results provide evidence of the plasticity of the floral morphology of Cleistes, especially the lip, and highlight that hitherto neglected characters, such as vegetative morphology, habitat, and floral scent, are particularly informative for the characterization of species and taxonomy of the genus. [ABSTRACT FROM AUTHOR]

Commonly attributed to orchids, the pollen movement in Vanilla has been associated with food deception and specific plant–pollinator relationships.This study investigated the role of flower rewards and pollinator specificity in the pollen transfer of a widely distributed member to the euglossinophilous Vanilla clade, V. pompona Schiede using data collected from Brazilian populations. These included investigations on morphology, light microscopy and histochemistry, and analysis of flowers scent using GC–MS. The pollinators and the mechanisms of pollination were recorded through focal observations.The yellow flowers of V. pompona are fragrant and offer nectar as reward. The major volatile compound of the V. pompona scent, carvone oxide, shows convergent evolution in Eulaema‐pollinated Angiosperms. The pollination system of V. pompona is not species‐specific, but its flowers are strongly adapted to pollination by large Eulaema males. Pollination mechanism is based in a combination of perfume collection and nectar seeking.The dogma of a species‐specific pollination system based on food deception in Vanilla has been broken with the increase in studies on this Pantropical orchid genus. Here, least three bee species and dual reward‐offering are involved in pollen transfer in V. pompona. Visitation frequency of bees collecting perfumes, used in courtship by male euglossines, is higher than in searching for food, as short‐lived young euglossine males seem to be more interested in sex than food. A pollination system based on offering both nectar and perfumes as resources is described for the first time in orchids. [ABSTRACT FROM AUTHOR]

During surveys conducted on Neotropical Vanilla, a new endemic species was found in the Brazilian campos rupestres of the Espinhaço Range. Here, this new remarkable Vanilla species, namely V. rupicola Pansarin & E.L.F. Menezes, is described and illustrated. A phylogeny for Vanilla is presented and the relationships between Neotropical species are discussed. The position of V. rupicola among Neotropical Vanilla is discussed within an evolutionary context. Vanilla rupicola is recognized by its rupicolous habit, its reptant stems, and its sessile and rounded leaves. This remarkable new taxon emerges in a clade that includes V. appendiculata Rolfe and V. hartii Rolfe. Vegetative and floral features support a close relationship between V. rupicola and sister taxa, mainly regarding the apical inflorescence (V. appendiculata), the type of appendages of the central crest of the labellum, and the labellar color pattern. Phylogenetic inference suggests that the circumscription of Neotropical Vanilla groups needs revision. [ABSTRACT FROM AUTHOR]

Introduction: Galeola lindleyana is a mycoheterotrophic orchid belonging to the tribe Vanilleae within the subfamily Vanilloideae. Methods: In this study, the G. lindleyana plastome was assembled and annotated, and compared with other Vanilleae orchids, revealing the evolutionary variations between the photoautotrophic and mycoheterotrophic plastomes. Results: The G. lindleyana plastome was found to include 32 protein-coding genes, 16 tRNA genes and four ribosomal RNA genes, including 11 pseudogenes. Almost all of the genes encoding photosynthesis have been lost physically or functionally, with the exception of six genes encoding ATP synthase and psaJ in photosystem I. The length of the G. lindleyana plastome has decreased to 100,749 bp, while still retaining its typical quadripartite structure. Compared with the photoautotrophic Vanilloideae plastomes, the inverted repeat (IR) regions and the large single copy (LSC) region of the mycoheterotrophic orchid's plastome have contracted, while the small single copy (SSC) region has expanded significantly. Moreover, the difference in length between the two ndhB genes was found to be 682 bp, with one of them spanning the IRb/SSC boundary. The Vanilloideae plastomes were varied in their structural organization, gene arrangement, and gene content. Even the Cyrtosia septentrionalis plastome which was found to be closest in length to the G. lindleyana plastome, differed in terms of its gene arrangement and gene content. In the LSC region, the psbA, psbK, atpA and psaB retained in the G. lindleyana plastome were missing in the C. septentrionalis plastome, while, the matK, rps16, and atpF were incomplete in the C. septentrionalis plastome, yet still complete in that of the G. lindleyana. Lastly, compared with the G. lindleyana plastome, a 15 kb region located in the SSC area between ndhB-rrn16S was found to be inverted in the C. septentrionalis plastome. These changes in gene content, gene arrangment and gene structure shed light on the polyphyletic evolution of photoautotrophic orchid plastomes to mycoheterotrophic orchid plastomes. Discussion: Thus, this study's decoding of the mycoheterotrophic G. lindleyana plastome provides valuable resource data for future research and conservation of endangered orchids. [ABSTRACT FROM AUTHOR]

The Vanilloideae (vanilloids) is one of five subfamilies of Orchidaceae and is composed of fourteen genera and approximately 245 species. In this study, the six new chloroplast genomes (plastomes) of vanilloids (two Lecanorchis, two Pogonia, and two Vanilla species) were decoded, and then the evolutionary patterns of plastomes were compared to all available vanilloid plastomes. Pogonia japonica has the longest plastome, with 158,200 bp in genome size. In contrast, Lecanorchis japonica has the shortest plastome with 70,498 bp in genome size. The vanilloid plastomes have regular quadripartite structures, but the small single copy (SSC) region was drastically reduced. Two different tribes of Vanilloideae (Pogonieae and Vanilleae) showed different levels of SSC reductions. In addition, various gene losses were observed among the vanilloid plastomes. The photosynthetic vanilloids (Pogonia and Vanilla) showed signs of stage 1 degradation and had lost most of their ndh genes. The other three species (one Cyrotsia and two Lecanorchis), however, had stage 3 or stage 4 degradation and had lost almost all the genes in their plastomes, except for some housekeeping genes. The Vanilloideae were located between the Apostasioideae and Cypripedioideae in the maximum likelihood tree. A total of ten rearrangements were found among ten Vanilloideae plastomes when compared to the basal Apostasioideae plastomes. The four sub-regions of the single copy (SC) region shifted into an inverted repeat (IR) region, and the other four sub-regions of the IR region shifted into the SC regions. Both the synonymous (dS) and nonsynonymous (dN) substitution rates of IR in-cooperated SC sub-regions were decelerated, while the substitution rates of SC in-cooperated IR sub-regions were accelerated. A total of 20 protein-coding genes remained in mycoheterotrophic vanilloids. Almost all these protein genes show accelerated base substitution rates compared to the photosynthetic vanilloids. Two of the twenty genes in the mycoheterotrophic species faced strong "relaxed selection" pressure (p-value < 0.05). [ABSTRACT FROM AUTHOR]

Inferring the evolutionary history of a group of closely related species can be challenging. Genetic diversity, structure, and multilocus phylogeny were studied to shed light on the evolutionary processes that shapes diversity in three closely related Lecanorchis species (L. cerina, L. suginoana, and L. thalassica). In this study, we surveyed nucleotide and genetic variation, respectively, using nuclear internal transcribed spacer 1 (nrITS1) and amplified fragment length polymorphism (AFLP) in individuals of Lecanorchis species. Both nrITS1 parsimonious and AFLP neighbor-joining trees showed paraphyly indicated that lineage sorting for these species may be incomplete. ITS1 haplotype sharing was found within L. cerina, within L. suginoana, and between L. suginoana and L. thalassica. Higher AFLP diversity was observed in L. cerina than that in L. suginoana and in L. thalassica, indicating larger population size in L. cerina. Two contrasting patterns of AFLP genetic differentiation between geographic neighbors relative to geographic distant populations were observed. Two major AFLP genetic components were found in individuals of Lecanorchis species examined. Individuals of L. cerina and of L. thalassica were classified into either component with high probabilities. Most individuals of L. suginoana were classified into one of these components, but two individuals showed apparent admixture of these components. The evidence of paraphyly, haplotype sharing, higher L. cerina diversity, sharing and admixture of genetic components, and the contrasting patterns of genetic differentiation suggest that both incomplete lineage sorting and secondary gene flow could have occurred in these closely related species, though at different temporal scale. [ABSTRACT FROM AUTHOR]

Pollination of the pantropical Vanilla has been linked to melittophily and food deception.Here we investigated the role of flower traits on the reproduction of Neotropical Vanilla. We also studied the evolution of pollination systems in order to understand the origin of production of flower resources and the diversification of pollinators in this orchid genus. Our study was founded on data of adaptations in flower morphology, production of resources, scent release, pollinators and breeding systems of Vanilla and presenting new data on reproductive biology of V. palmarum. Data on reproductive biology of Vanilla were mapped onto a phylogeny to address our queries on the evolution of pollination systems in this genus.Vanilla palmarum shows a mixed mating system, with its facultative autogamous flowers being pollinated by hummingbirds. Its yellow flowers are scentless and produces nectar. Mapping of the pollination system onto trees resulted in one origin for bird pollination and at least two origins for autogamy in Vanilla. Nectar secretion has a single origin in the Neotropical thick‐leafed lineage.Bird pollination of Vanilla is shown for the first time. The origin of ornithophily within a bee‐pollinated clade is supported by flower morphology. Floral transitions to ornithophily have been favoured by the occupation of a distinct niche from that of the other thick‐leafed Vanilla species. Despite its specialized pollination, V. palmarum is autogamous. A mixed mating system can promote reproductive assurance in the case of a decline in pollinator populations, or in areas where pollinator services are irregular or absent. [ABSTRACT FROM AUTHOR]

In many flowering plants the attraction of pollinators is related to some kind of deception. Pollination by food-deception occurs in several angiosperm groups and is particularly widespread in orchids. Despite the apparent evolutionary success of pollination by food-deception, food-deceptive orchids show a low level of fruit set. Although studies are scarce, the pollination of Vanilla has been usually associated with nectar-deception. In Vanilla spp. (Vanilla bahiana , V. bicolor , V. chamissonis , V. edwallii , V. hartii , V. phaeantha , V. paulista , V. planifolia , V. ribeiroi and V. pompona), understanding the factors associated with pollinators is essential, since in vanilla production a cumbersome process of supplementary manual pollination is necessary to increase fruit set, which is frequently low under natural conditions. The production of floral rewards was investigated here in ten Neotropical Vanilla spp. based on morpho-anatomy and histochemical analyses of flowers. Six species (Vanilla bahiana , Vanilla bicolor , Vanilla chamissonis , Vanilla hartii , Vanilla phaeantha and Vanilla pompona) offer nectar as a reward. In Vanilla ribeiroi , the long trichomes of the labellum base are rich in starch grains and proteins, characteristic of food-hairs. The only secretory structures of Vanilla edwallii are osmophores on the inner surface of the labellum that are related to the attraction of oil-collecting bees as pollinators. Vanilla spp. possess sepaline and labellar osmophores. Inside the labellum the osmophores are arranged along longitudinal lines and act as resource guides. Although it is widely known that Vanilla flowers attract pollinators by nectar deception, the present data reveal that there may be a lack of knowledge regarding pollination in this group since the offer of nectar appears to be a common condition, at least for the euglossine-pollinated Neotropical clade. The remaining Neotropical groups exhibit other pollination strategies, such as the production of food-hairs and fragrances that attract oil-collecting bees to the flowers. The study of Vanilla pollination is extremely important because the need for manual pollination, added to the ripening and curing time, causes vanilla to be one of the most expensive spices in the world. According to the data presented here, the pollination systems of vanilla are much more diverse than classical "food deception". [ABSTRACT FROM AUTHOR]

The Vanilloideae (vanilloids) is one of five subfamilies of Orchidaceae and is composed of fourteen genera and approximately 245 species. In this study, the six new chloroplast genomes (plastomes) of vanilloids (two Lecanorchis, two Pogonia, and two Vanilla species) were decoded, and then the evolutionary patterns of plastomes were compared to all available vanilloid plastomes. Pogonia japonica has the longest plastome, with 158,200 bp in genome size. In contrast, Lecanorchis japonica has the shortest plastome with 70,498 bp in genome size. The vanilloid plastomes have regular quadripartite structures, but the small single copy (SSC) region was drastically reduced. Two different tribes of Vanilloideae (Pogonieae and Vanilleae) showed different levels of SSC reductions. In addition, various gene losses were observed among the vanilloid plastomes. The photosynthetic vanilloids (Pogonia and Vanilla) showed signs of stage 1 degradation and had lost most of their ndh genes. The other three species (one Cyrotsia and two Lecanorchis), however, had stage 3 or stage 4 degradation and had lost almost all the genes in their plastomes, except for some housekeeping genes. The Vanilloideae were located between the Apostasioideae and Cypripedioideae in the maximum likelihood tree. A total of ten rearrangements were found among ten Vanilloideae plastomes when compared to the basal Apostasioideae plastomes. The four sub-regions of the single copy (SC) region shifted into an inverted repeat (IR) region, and the other four sub-regions of the IR region shifted into the SC regions. Both the synonymous (dS) and nonsynonymous (dN) substitution rates of IR in-cooperated SC sub-regions were decelerated, while the substitution rates of SC in-cooperated IR sub-regions were accelerated. A total of 20 protein-coding genes remained in mycoheterotrophic vanilloids. Almost all these protein genes show accelerated base substitution rates compared to the photosynthetic vanilloids. Two of the twenty genes in the mycoheterotrophic species faced strong “relaxed selection” pressure (p-value < 0.05).

Vanilla bean is the second most expensive spice in the world. While widely cultivated for centuries due to its importance for industry and gastronomy, its dispersers are unknown.In the present study, I investigated the system of seed dispersal of Neotropical vanillas based on experimental observations, the morpho‐anatomy of fruits and seeds, and the effect of dormancy breakdown on seed germination.My results show the central cavity of the fruit contains copious amounts of seed with sclerified coats that are consumed by birds. The combination of gradually opening dehiscent fruits and a well‐developed mesocarp rich in raphide idioblasts reinforces the idea that seed dispersal in Vanilla is more adapted to non‐chewing animals. The digestive acids of birds sclerify the hard seed coats, breaking dormancy and promoting germination at the beginning of the wet season, which is fundamental for seedling survival and for the establishment of plants in the early stages of development during the rainy season.Zoochory in Vanilla is show for the first time. The chemical scarification of the seed coat is crucial for synchronizing the biological processes involved in seed germination. My evidence on endozoochory and the processes involved in seed germination of Neotropical vanillas provides new insights into understanding of the early evolution of seed dispersal in orchids. [ABSTRACT FROM AUTHOR]

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.

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]

During surveys conducted on Neotropical Vanilla , a new endemic species was found in the Brazilian campos rupestres of the Espinhaço Range. Here, this new remarkable Vanilla species, namely V.rupicola Pansarin & E.L.F. Menezes, is described and illustrated. A phylogeny for Vanilla is presented and the relationships between Neotropical species are discussed. The position of V.rupicola among Neotropical Vanilla is discussed within an evolutionary context. Vanillarupicola is recognized by its rupicolous habit, its reptant stems, and its sessile and rounded leaves. This remarkable new taxon emerges in a clade that includes V.appendiculata Rolfe and V.hartii Rolfe. Vegetative and floral features support a close relationship between V.rupicola and sister taxa, mainly regarding the apical inflorescence ( V.appendiculata ), the type of appendages of the central crest of the labellum, and the labellar color pattern. Phylogenetic inference suggests that the circumscription of Neotropical Vanilla groups needs revision., Competing Interests: No conflict of interest was declared., (Emerson Ricardo Pansarin, Euler da Luz Fernandes Menezes.)

Introduction: Galeola lindleyana is a mycoheterotrophic orchid belonging to the tribe Vanilleae within the subfamily Vanilloideae., Methods: In this study, the G. lindleyana plastome was assembled and annotated, and compared with other Vanilleae orchids, revealing the evolutionary variations between the photoautotrophic and mycoheterotrophic plastomes., Results: The G. lindleyana plastome was found to include 32 protein-coding genes, 16 tRNA genes and four ribosomal RNA genes, including 11 pseudogenes. Almost all of the genes encoding photosynthesis have been lost physically or functionally, with the exception of six genes encoding ATP synthase and psaJ in photosystem I. The length of the G. lindleyana plastome has decreased to 100,749 bp, while still retaining its typical quadripartite structure. Compared with the photoautotrophic Vanilloideae plastomes, the inverted repeat (IR) regions and the large single copy (LSC) region of the mycoheterotrophic orchid's plastome have contracted, while the small single copy (SSC) region has expanded significantly. Moreover, the difference in length between the two ndh B genes was found to be 682 bp, with one of them spanning the IRb/SSC boundary. The Vanilloideae plastomes were varied in their structural organization, gene arrangement, and gene content. Even the Cyrtosia septentrionalis plastome which was found to be closest in length to the G. lindleyana plastome, differed in terms of its gene arrangement and gene content. In the LSC region, the psb A, psb K, atp A and psa B retained in the G. lindleyana plastome were missing in the C. septentrionalis plastome, while, the mat K, rps 16, and atp F were incomplete in the C. septentrionalis plastome, yet still complete in that of the G. lindleyana . Lastly, compared with the G. lindleyana plastome, a 15 kb region located in the SSC area between ndh B -rrn 16S was found to be inverted in the C. septentrionalis plastome. These changes in gene content, gene arrangment and gene structure shed light on the polyphyletic evolution of photoautotrophic orchid plastomes to mycoheterotrophic orchid plastomes., Discussion: Thus, this study's decoding of the mycoheterotrophic G. lindleyana plastome provides valuable resource data for future research and conservation of endangered orchids., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Zhou, Chen, Qiu, Liu and Guo.)

Background and Aims Most fully mycoheterotrophic (MH) orchids investigated to date are mycorrhizal with fungi that simultaneously form ectomycorrhizas with forest trees. Only a few MH orchids are currently known to be mycorrhizal with saprotrophic, mostly wood-decomposing, fungi instead of ectomycorrhizal fungi. This study pro vides evidence that the importance of associations between MH orchids and saprotrophic non-Rhizoctonia fungi is currently under-estimated. *Methods Using microscopic techniques and molecular approaches, mycorrhizal fungi were localized and identified for seven MH orchid species from four genera and two subfamilies, Vanilloideae and Epidendroideae, growing in four humid and warm sub-tropical forests in Taiwan. Carbon and nitrogen stable isotope natural abundances of MH orchids and autotrophic reference plants were used in order to elucidate the nutritional resources utilized by the orchids. *Key Results Six out of the seven MH orchid species were mycorrhizal with either wood- or litter-decaying saprotrophic fungi. Only one orchid species was associated with ectomycorrhizal fungi. Stable isotope abundance patterns showed significant distinctions between orchids mycorrhizal with the three groups of fungal hosts. *Conclusions Mycoheterotrophic orchids utilizing saprotrophic non-Rhizoctonia fungi as a carbon and nutrient source are clearly more frequent than hitherto assumed. On the basis of this kind of nutrition, orchids can thrive in deeply shaded, light-limiting forest understoreys even without support from ectomycorrhizal fungi. Sub-tropical East Asia appears to be a hotspot for orchids mycorrhizal with saprotrophic non-Rhizoctonia fungi. [ABSTRACT FROM AUTHOR]

Vanilloideae comprises 15 genera distributed worldwide, among which are Vanilla and Epistephium (tribe Vanilleae). Based on field and laboratory investigations, the pollination biology of V. dubia and E. sclerophyllum was analysed. The former was surveyed in a semi-deciduous mesophytic forest at the biological reserve of Serra do Japi and in a marshy forest at the city of Pradópolis, southeastern Brazil. The latter was examined in rocky outcrop vegetation in the Chapada Diamantina, northeastern Brazil. In the studied populations, the tubular flowers of V. dubia and E. sclerophyllum were pollinated by bees. Pollen was deposited on either their scutellum ( V. dubia) or scutum ( E. sclerophyllum). The mentum region of V. dubia is dry, whereas that of E. sclerophyllum presents a small quantity of dilute nectar. Flowers of E. sclerophyllum are scentless, while those of V. dubia are odoriferous. Although V. dubia is self-compatible, it needs a pollinator to produce fruit. In contrast, E. sclerophyllum sets fruit through spontaneous self-pollination, but biotic pollination also occurs. Both species are primarily adapted to pollination by euglossine bees. Pollination by Euglossina seems to have occurred at least twice during the evolution of Vanilleae. Furthermore, shifts between rewarding and reward-free flowers and between autogamous and allogamous species have been reported among vanillas. [ABSTRACT FROM AUTHOR]

The genus Vanilla is the most diverse in Vanilloideae, with ca 90 species distributed among tropical regions. Despite their economic importance, studies on pollination of Vanilla are very scarce and data on pollinators of species endemic to Brazil are lacking. Based on fieldwork and laboratory investigations, the floral biology of V. edwallii was studied. The pollinators and pollination process were recorded at the Serra do Japi reserve, state of São Paulo, southeastern Brazil, and the presence of floral reward was also investigated. Vanilla edwallii blooms in summer. The lateral inflorescences produce up to four pale green flowers. The white labellum is united to the base of the column forming a mentum. In the studied population V. edwallii is pollinated by Epicharis (Hoplepicharis) affini s, where the males exhibit a territorial behavior, defending flowers from other possible flower visitors. The pollen is deposited on the scutellum of bees when they abandon the flower. The mentum region is dry, suggesting no nectar production. The only secretory structures are osmophores dispersed on the inner surface of the lip responsible for production of a sweet fragrance, which together with color and morphology of flowers is related to bee attraction. The labellum is rich in mucilaginous cells, while the mucilaginous substance is retained inside the cells. The histochemical analysis also detected the presence of phenolic compounds and starch concentrated mainly at the adaxial surface of the lip and around the vascular bundles. [ABSTRACT FROM AUTHOR]

Abstract: The tribe Pogonieae of Vanilloideae (Orchidaceae) consists of six genera, including Pogoniopsis, a myco-heterotrophic taxon with morphological characteristics distinct from the remaining of the tribe. A hypothesis about the phylogeny of the tribe was inferred, involving all currently recognized genera, based on isolated and combined sequence data of 5.8S, 18S and 26S (nrDNA) regions using parsimony and Bayesian analyses. Phylogenetic analyses show that inclusion of Pogoniopsis turns the tribe Pogonieae paraphyletic. All analyses reveal that Pogoniopsis is closely related to members of Epidendroideae. The pantropical Vanilla is monophyletic if Dictyophyllaria is assumed as synonym of Vanilla. Members of Pogonieae are pollinated by several groups of solitary and social bees, two pollination systems being recognized: reward-producing and deceptive. The molecular phylogeny suggests that ancestrals related to Pogonieae gave rise to two evolutionary lines: a tropical one with reward production of flowers, and a predominantly temperate regions invading line with deceptive flowers. Reward-producing flowers characterize the South and Central American clade (=Cleistes), while deceptive pollination is prominent in the clade that includes North American-Asiatic taxa plus the Amazonian genus Duckeella. [Copyright &y& Elsevier]

Background and Aims: Most molecular phylogenetic studies of Orchidaceae have relied heavily on DNA sequences from the plastid genome. Nuclear and mitochondrial loci have only been superficially examined for their systematic value. Since 40% of the genera within Vanilloideae are achlorophyllous mycoheterotrophs, this is an ideal group of orchids in which to evaluate non-plastid gene sequences. [ABSTRACT FROM PUBLISHER]

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The chromosome numbers of forty-one Brazilian species belonging to 11 genera of preferentially terrestrial orchids (subfamilies Cypripedioideae, Spiranthoideae, Orchidoideae, and Vanilloideae) were examined. Previous records for these subfamilies were reviewed in order to identify the ancestral chromosome numbers of terrestrial orchids. The variation observed within the subfamilies Spiranthoideae (2n=28, 36, 46, 48 and 92), and Orchidoideae (2n=42, 44, ca. 48, ca. 80, 84, and ca. 168) was similar to that previously reported in the literature. In the subfamily Spiranthoideae, some species of Prescottia (subtribe Prescottiinae) and some genera of Spiranthinae showed a bimodal karyotype with one distinctively large pair of chromosomes. The analysis of chromosome numbers of the genera in subfamilies revealed the predominance of the polyploid series 7, 14, 21, 28, 42 with a dysploid variation of ±1 in each ploidy level. These results suggest that the basic chromosome number of terrestrial orchids is x1=7 for the subfamilies Spiranthoideae and Orchidoideae, as well as other Epidendroid orchids, and that the majority of the genera are composed of palaeopolyploids. [ABSTRACT FROM AUTHOR]

cL DNA sequences, nuclear ribosomal ITS DNA sequences, morphology, and combined evidence. All these matrices produced patterns that agree on the broader Phylogenetic relationship within the clade. Duckeella is sister to all Pogoniinae, South American species of Cleistes are monophyletic, Pogonia is monophyletic and part of a larger clade of temperate taxa ( Isotria, Pogonia, and Cleistes divaricata) from North America and Asia. The structure of the cladograms and the high levels of bootstrap support strongly indicate that the genus Cleistes is paraphyletic. The disjunction between tropical South American and temperate North American taxa as well as the disjunction between Pogonia ophioglossoides in eastern North America with P. minor and P. Japonica in eastern Asia are best explained by speciation following a northward longdistance dispersal and subsequent northwestward migration via Bering land bridges in the Tertiary. This phylogenetic study adds an additional herbaceous example to the growing list of plants that demonstrate this classical biogeographic pattern. [ABSTRACT FROM AUTHOR]