Terrestrial Orchid Species Research Articles

The chloroplast genome of Cephalanthera nanchuanica (Orchidaceae): comparative and phylogenetic analysis with other Neottieae species

BackgroundCephalanthera nanchuanica is a terrestrial orchid species and has been red listed as a second-grade protected plant due to its limited distributions in China. Initially classified within a monotypic genus Tangtsinia, this species was later reassigned to Cephalanthera based on morphological and molecular data. However, previous phylogenetic analyses of Cephalanthera using several segment sequences exhibited a low discriminatory power in delineating its relationships.ResultsIn this study, we characterized and comparatively analyzed the complete chloroplast (cp) genome of C. nanchuanica with those of six previously reported Cephalanthera species. Our findings revealed that the cp genome of C. nanchuanica had the typical quadripartite structure, with a size of 161,365 bp and a GC content of 37.27%. A total of 113 unique genes were annotated, among which nearly half of protein-encoding genes (RSCU > 1) showed a preference in codon usage. No structural rearrangements were observed among the cp genomes of Cephalanthera species, except for C. humilis, which displayed structural alterations due to gene loss, relocation, and inverted repeat (IR) expansion/contraction. The cp genomes of Cephalanthera species were highly conserved, with only a small number of SSRs detected, most of which preferred A/T bases. Comparative analysis of cp genomes indicated that IR and coding regions were less divergent than single copy and non-coding regions and eight mutational hotspots were identified. Phylogenetic analysis suggested that the tribe Neottieae was a monophyletic group, divided into five clades. Palmorchis was the earliest-diverging lineage, followed by Cephalanthera. Diplandrorchis was deeply nested within Neottia, forming a clade. Aphyllorchis and Limodorum formed another clade, sister to Epipactis. Within the Cephalanthera clade, C. nanchuanica was sister to C. falcata with a strong support.ConclusionsThis study demonstrated that the cp genome characters of C. nanchuanica are highly similar to those of other Cephalanthera species, except for the mycoheterotrophic species C. humilis. Although the cp genomes of Cephalanthera species (excluding C. humilis) exhibited conservation in genome structure and sequence, SSR repeats and mutational hotspots were identified, which could potentially serve as as molecular markers for distinguishing Cephalanthera species. The phylogenetic analysis based on the protein-coding genes provided high-resolution support for the infrageneric classification. Therefore, cp genome data will be instrumental in resolving the phylogeny of the genus Cephalanthera.

Pollination by multiple species of nectar foraging Hymenoptera in Prasophyllum innubum, a critically endangered orchid of the Australian Alps

Context Australia has numerous threatened species of terrestrial orchid, with a particularly high incidence of rarity in the genus Prasophyllum R.Br. Although there has been research on mycorrhizal associations and propagation, little is known about the reproductive ecology of threatened Prasophyllum. Understanding which animals are responsible for pollination and the impact of herbivores on reproduction may inform conservation actions. Aims For the nationally Critically Endangered Prasophyllum innubum, we aimed to determine the pollinator species, test for self-pollination, quantify levels of reproductive success and herbivory, and identify herbivores. Methods Pollinator observations were undertaken at wild populations of P. innubum, whereas an experiment testing for self-pollination was undertaken in shadehouse conditions. We quantified reproductive success and herbivory at two populations and attempted to identify herbivores using game cameras. Key results Pollination occurred via three species of bee and a sphecid wasp, all of which attempted feeding on floral nectar. Fruit set averaged 72–84% at wild sites, whereas only 6% of flowers set fruit via self-pollination when insects were excluded. Just 4% of inflorescences were completely consumed by herbivores, and no herbivory was captured on camera. Conclusions P. innubum has a generalist rewarding pollination system that confers high levels of reproductive success, with herbivory having little impact on reproduction. Implications Pollinator availability is unlikely to restrict conservation translocation site selection of P. innubum because of a generalist pollination system. If herbivores are a threat for this species, it is likely to be through alteration of habitat rather than direct grazing.

Update on the terrestrial orchid flora of the Tacana volcano and close area, Chiapas, Mexico

Objective: To assess the number of terrestrial orchid species on the Tacaná volcano, Chiapas, and to empirically observe distribution/elevation patterns and ecological conditions. Design/Methodology/Approach: Random line transect sampling, over two years, for a total of 8 sites, each starting from the vicinity of rural villages. Samples were deposited in the CICY herbarium and analysed using dichotomous keys and field photographs. New records were compared with the GBIF data distribution. Results: 52 different taxa have been identified. 24 species are new records for the Soconusco region, where the Tacaná volcano is located. In this way, the Soconusco region becomes the richest Mexican region for the number of orchid species, joining a total of 351 species. Study Limitations/Implications: Building an accurate prediction model based on environmental and topographic variables could suggest microsites within the Tacaná Park that we have not visited for practical and technical reasons. Findings/Conclusions: The total number of taxa in the Soconusco region increases to 351. Terrestrial orchids are not usually studied in depth in tropical places, but they are also important in the ecological balance of the natural site. A specific inventory could show more richness of tropical ecosystems

KEANEKARAGAMAN JENIS ANGGREK DI JALUR PENDAKIAN WIRAYANA GUNUNG CAKRABUANA KABUPATEN MAJALENGKA

The existence of orchids in nature continues to decline due to habitat destruction and overexploitation. Conservation efforts that have been carried out so far have often experienced difficulties due to insufficient data and information as a basis for management, including conservation areas. The more widespread forest destruction will result in these species being threatened with extinction. This study aims to determine the diversity of orchid species, on the Wirayana Mount Cakrabuana Climbing Path. The information is expected to provide an initial contribution to the area management and orchid conservation efforts on the Wirayana Mount Cakrabuana Climbing Path. This research was conducted by means of a vegetation survey, sampling and documentation by exploring the existence of orchids. The sampling technique used the path transect method. The number of transects used is one line transect with a line length of 1500 m with a total of 22 sample plots. Data analysis was carried out by calculating the Important Value Index (INP), Species Dominance Index (Di) and Species Diversity Index (H'). The results showed that in the natural forest area of ​​Mount Cakrabuana there were 22 species of individuals which included 7 species of terrestrial orchids and 15 species of epiphytic orchids with a total of 243 individuals found. From the results of the calculation of species diversity, it is stated that the diversity of orchid species in the natural forest area of ​​Mount Cakrabuana is classified as moderate (2,973). This information is very important, especially for area managers in preserving the biodiversity of Mount Cakrabuana, especially orchids in the future.

Inventory of Orchid Species in Customary Forest Area of Cipta Karya Village, Sungai Betung District, Bengkayang Regency

Orchids are one of the flowering plants that have many species and are widely distributed, as well as having different attractions and characteristics in each species and habitat. The aim of this research to inventory the types of orchids in Customary Forest Area of Cipta Karya Village, Bengkayang Regency. The research was conducted using the cruise method. The characteristics observed were the morphology of orchids such as roots, pseudobulbs, stems, leaves, and flowers. The inventory results found 13 species of orchids. Epiphytic orchids were found more commonly in this area, with a total of 9 species, while terrestrial orchids were found with 4 species. The epiphytic orchid species foundware composed of Appendicula sp., Bulbophyllum sp., Coelogyne speciosa, Cymbidium sp., Dendrobium crumenatum, Dendrobium anosmum, Luisia sp., Micropera pallida and Oberonia sp. The terrestrial orchid species found ware composed of Acanthephippium javanicum, Malaxis latifolia, Nephelaphyllum pulchrum, and Spathoglottis plicata.

Terrestrial orchid diversity in Hosanagara taluk of Shimogga district Central Western Ghats region of KarnatakaTerrestrial orchid diversity in Hosanagara taluk of Shimogga district Central Western Ghats region of Karnataka.

The current article evaluates the study of terrestrial orchids in the Hosanagara taluk of Shimogga district, reports a total of 30 terrestrial orchid species in the Hosanagara taluk region Shimogga district Karnataka from the period of January 2019-January 2022, and provides information on their distribution, phenology aspects, and biological status in the Hosanagara taluk of Shimogga district. Extensive field surveys were carried out periodically in different parts of the taluk, particularly in grasslands and hilly regions, to study the plant's diversity and phenological character. It was noticed that, when compared to other species, the Habenaria species is richly distributed in the Hosanagara taluk region. During field trips, some anthropogenic activities that have a significant impact on the diversity of terrestrial orchids were also observed. To learn more about the variety and current state of terrestrial orchid species in the Hosanagara taluk in the Shimogga District of Karnataka, further research must be conducted.

Terrestrial Orchid Diversity in Sagara Taluk of Shimogga District Central Western Ghats Region of Karnataka

The current article evaluates the study of terrestrial orchids in Sagara taluk of Shimogga district, reports total 26 terrestrial orchid species in Sagara taluk region Shimogga district Karnataka from the period of January 2019-January 2022 and provides information on their distribution, phenology aspects and biological status in the district. Extensive field surveys were carried out periodically in different part of the taluk particularly in grasslands and hilly region to study the diversity and phenological character of the plant. It was noticed that, when compared to other species, the Habenaria species is richly distributed in Sagara taluk regions. During field visits also noticed some anthropogenic activities highly effects on the diversity of the terrestrial orchids. The further study has to be carried out to get more information related to diversity and current status of terrestrial orchid species in Sagara taluk region of Shimogga district Karnataka.

Pollinators of Epiphytic and Terrestrial Orchid Species in Bhutan

Fruit set in the orchids in the wild in Bhutan seems to be generally higher than in surrounding countries in Asia. To obtain more knowledge on local pollinators in Bhutan, pollinators were photographed in the private Orchidarium, over a period of six years. A total of 10 insect species, belonging to the orders of Diptera (true flies), Hymenoptera (ants, bees, wasps) and Coleoptera (beetle), were seen pollinating the flowers of 15 different orchid species (14 epiphytic and 1 terrestrial). Several pollinators are reported for the first time as the pollinators of orchids. Our study provides a first glimpse into the pollination biology of Bhutanese orchids and could be used for the reintroduction of the locally extinct orchid pollinators elsewhere in Asia.

In vitro asymbiotic seed germination, protocorm formation, and plantlet development of Orchis simia Lam.: A threatened terrestrial orchid species

• Seed germination and plantlet growth were impacted by organic constituents and nitrogen sources. • Individual application of organic nitrogen compounds led to higher germination efficiencies. • The present protocol could be used for large-scale in vitro micropropagation of terrestrial orchids. The present study examined the seed morphometric and viability, asymbiotic seed germination, protocorm formation, and plantlet growth in Orchis simia Lam., an at-risk Euro-Mediterranean terrestrial orchid species. Furthermore, tissue histology pattern in vitro grown plantlets and field-established was compared. After one month, shoot and root primordia started to grow on developing protocorms and small plantlets became visible after 2–3 subculturing. Asymbiotic in vitro seed germination and plantlet growth attributes were significantly ( P <0.05) impacted by both type of main organic constituent and nitrogen sources. The seeds sown on media supplemented with pineapple juice (PJ) and casein hydrolysate (CH) had the highest germination percentage. In terms of required days to see the first signs of germination, CW+AV treatment brings about the fastest germination (6.8 ± 0.20 days). Protocorms grown on the media comprising PJ in combination with Aminoven (AV) or casein hydrolysate (CH) or Pep showed higher dimensions and therefore higher weight (% 450 increase) compared to protocorms grown on other media. Altogether, treatments with higher germination percentage, faster germination, and bigger protocorms finally resulted in better plantlet growth. Acclimatization of in vitro grown plantlets occurred by converting scattered vascular tubes into fully developed xylem and phloem vessels facilitating sap flow. Taking into account the fragmentation of O. simia populations in the Middle East and the Euro-Mediterranean basin mainly due to tuber overharvesting and climate change, the present procedure could be used for large-scale multiplication of in vitro raised seedlings to re-introduce into endangered regions.

In vitro culture conditions for asymbiotic germination and seedling development of Anacamptis pyramidalis (L.) Rich. and Gymnadenia conopsea (L.) R. Br.

• Positive influence of MM medium on germination of A. pyramidalis and G. conopsea was determined. • Germination was influenced by full darkness and nutrient medium enriched with organic aditives. • In seedling growth, 2iP initiated the formation of the aboveground part of G. conopsea. • In A. pyramidalis, Kin initiated the leaf formation, while Ba promote root formation. Protocols for asymbiotic seed germination and seedling development of two terrestrial orchid species – Gimnadenia conopsea and Anacamptis pyramidalis are presented in this paper. Detail examination covered nutrient media: Knudson C (KC) and Malmgren (MM); organic supplements: coconut water (CW), pineapple juice (PJ), peptone (PE), casein hydrolysate (CA) and glutamine (A); different lighting conditions – 0/24 Light / Dark (L / D) and 16/8 (L / D) as well as cytokinins: 6-benzyladenine (BA), kinetin (Kin), and 6- (γ, γ-dimethylallylamino) purines (2 -iP) aiming to assess asymbiotic seed germination in controlled in vitro conditions, to define the optimal protocol for their mass propagation. The obtained results indicate that the nutrient medium MM and conditions of complete darkness encourage seed germination in both investigated species, while the organic supplements amendment resulted in a shortened period necessary for seed germination as well as a significantly higher percentage of germination. In Gymnadenia conopsea , the highest percentage of germination (73,79%) accompanied by the highest embryo/protocorm morphometric characteristics (1.40 mm average height, 1.21 mm average width, and 0.30 mm average shoot height) was achieved on MM-CW nutrient medium. A similar result was observed for Anacamptis pyramidalis with 69,88% germinated seeds on MM-CW nutrient medium, while the highest morphometric values were 1.10 mm (on MM-CW) for height, 1.00 mm (on MM-PE) for width and 0.57 mm (on MM-PE) for bud height. On the contrary, the results obtained on nutrient medium KC and under the 16/8 L / D lighting conditions indicate the inhibitory effect of these conditions on the seeds germination in examined species. A experiment with chitokinin treatments indicates that the best result in G. conopsea was achieved on the medium with the addition of 0.3 mg L −1 2iP with 5.33 mm for plant height, 1,13 root numbers and 12.26 mm root lenght, while in A. pyramidalis 0.3 mg L −1 Kin emerged as the most suitable for the development of the upper part of the plant (3.33 mm), while the medium enriched with 0.3 mg L −1 BA had a positive effect on the formation of the root system.

Inventarisasi Keanekaragaman Anggrek (Orchidaceae) di Kecamatan Polinggona Kabupaten Kolaka

Orchid is type of flowering plant that has economic value because most of them have beautiful and attractive flowers. The existence species of orchids in nature is increasingly threatened due to the high activity of land conversion and hunting for the orchids themselves. The purpose of this study was determine the diversity of orchids spesies in Polinggona, Kolaka district Southeast Sulawesi. The research used an explorative and interview method. Based on the observations, there were 31 species of epiphytic orchids, 5 species of terrestrial orchids, one semi-terrestrial orchid and there are 6 species of orchids is unidentified.The results of vertical distribution on the host tree, the epiphytic orchids found growing in all zones were Pomatocalpa spicata and Dendrobium ephemerum and mostly the epiphytic orchids in the observation site grew in zone III, specifically at the base of branching of its host tree.Terrestrial orchid type Arundina graminifolia has the most limited distribution compared to other terrestrial orchid species. The types of terrestrial and semi-terrestrial orchids that were found were all close to the river flow.

Modeling the effect of climate change on the distribution of threatened medicinal orchid Satyrium nepalense D. Don in India.

It is vital to understand the distribution area of a threatened plant species for its better conservation and management planning. Satyrium nepalense (family: Orchidaceae) is a threatened terrestrial orchid species with valuable medicinal and nutritional properties. The survival of S. nepalense in wild conditions has been challenged by increasing global surface temperature. Hence, understanding the impact of climate change on its potential distribution is crucial to conserve and restore this species. In present study, Maxent species distribution modeling algorithm was used to simulate the current distribution of S. nepalense in India and predict the possible range shift in projected future climate scenarios. A set of 19 bioclimatic variables from WorldClim database were used to predict the potential suitable habitats in current climatic condition and four Representative Concentration Pathway (RCP 2.6, 4.5, 6.0, and 8.5) scenarios by integrating five General Circulation Models (GCMs) for future distribution modeling of species for the years 2050 and 2070. Furthermore, change analysis was performed to identify the suitable habitat in current and future climate for delineating range expansion (gain), contraction (loss), and stable (no change) habitats of species. The Maxent model predicted that ~ 2.38% of the geographical area in India is presently climatically suitable for S. nepalense. The key bioclimatic variables affecting the distribution of studied species were the mean temperature of warmest quarter, mean temperature of wettest quarter, precipitation of warmest quarter, and temperature seasonality. Under future climate change scenarios, the total suitable habitat of S. nepalense will increase slightly in the Himalayan region and likely to migrate towards northward, but in the Western Ghats region, the suitable areas will be lost severely. The net habitat loss under four RCP scenarios was estimated from 26 to 39% for the year 2050, which could further increase from 47 to 60% by the year 2070. The finding of the predictive Maxent modeling approach indicates that warming climates could significantly affect the potential habitats of S. nepalense and hence suitable conservation measures need to be taken to protect this threatened orchid species in wild conditions.

Range Size and Niche Breadth as Predictors of Climate-Induced Habitat Change in Epipactis (Orchidaceae)

While there is mounting evidence that ongoing changes in the climate system are shifting species ranges poleward and to higher altitudes, responses to climate change vary considerably between species. In general, it can be expected that species responses to climate change largely depend on how broad their ecological niches are, but evidence is still scant. In this study, we investigated the effects of predicted future climate change on the availability of suitable habitat for 14 Epipactis (Orchidaceae) species, and tested whether habitat specialists would experience greater changes in the extent of their habitats than habitat generalists. We used Maxent to model the ecological niche of each species in terms of climate, soil, elevation and land-use and projected it onto climate scenarios predicted for 2061–2080. To test the hypothesis that temperate terrestrial orchid species with small ranges or small niche breadths may be at greater risk under climate change than species with wide ranges or large niche breadths, we related niche breadth in both geographic and environmental space to changes in size and location of suitable habitat. The habitat distributions of half of the species shifted northwards in future projections. The area of suitable habitat increased for eight species but decreased for the remaining six species. If expansion at the leading edge of the distribution was not possible, the area of suitable habitat decreased for 12 species. Species with wide niche breadth in geographic space experienced greater northwards expansions and higher habitat suitability scores than species with small niche breadth. Niche breadth in environmental space was not significantly related to change in habitat distribution. Overall, these results indicate that terrestrial orchid species with a wide distribution will be more capable of shifting their distributions under climate change than species with a limited distribution, but only if they are fully able to expand into habitats at the leading edge of their distributions.

Germination and initial development in vitro, and acclimatization of Oeceoclades maculata (Orchidaceae), aiming at its reintroduction in natural environments

Oeceoclades maculata is a terrestrial orchid species that has potential for commercial purposes. Taking that into consideration, the present investigation aimed at studying its germination and initial development in vitro as well as its acclimatization. The influence of Murashige and Skoog (MS), Knudson C (KC), and Vacin and Went (VW) media in the presence and absence of 0.3% activated charcoal on in vitro germination and protocorm development were investigated. The effects of different concentrations of BA in combination with 0.5 mg L-1 NAA on seedling multiplication and growth were evaluated. The possibility of using dark-grown stem segments for micropropagation and acclimatization under laboratory and field conditions was also assessed. The results indicated that the most adequate media for germination were full-strength MS enriched with activated charcoal or KC supplemented with 1.5 mg L-1 BA in combination with 0.5 mg L-1 NAA. In terms of protocorm development, KC supplemented with 1.5 mg L-1 BA alone or in combination with 0.5 mg L-1 NAA provided the best results. The addition of 1.5 mg L-1 BA in combination with 0.5 mg L-1 NAA to KC medium favored the best results for seedling multiplication and development. The use of dark-grown stem segments is a viable alternative for the micropropagation of O. maculata. Regarding acclimatization, 100% survival of plants was observed during the initial phases and under field conditions average survival was 53.33%.

Inorganic phosphorus nutrition in green-leaved terrestrial orchid seedlings.

Many terrestrial orchids have an obligate dependence on their mycorrhizal associations for nutrient acquisition, particularly during germination and early seedling growth. Though important in plant growth and development, phosphorus (P) nutrition studies in mixotrophic orchids have been limited to only a few orchid species and their fungal symbionts. For the first time, we demonstrate the role of a range of fungi in the acquisition and transport of inorganic P to four phylogenetically distinct green-leaved terrestrial orchid species (Diuris magnifica, Disa bracteata, Pterostylis sanguinea and Microtis media subsp. media) that naturally grow in P-impoverished soils. Mycorrhizal P uptake and transfer to orchids was determined and visualized using agar microcosms with a diffusion barrier between P source (33P orthophosphate) and orchid seedlings, allowing extramatrical hyphae to reach the source. Extramatrical hyphae of the studied orchid species were effective in capturing and transporting inorganic P into the plant. Following 7 d of exposure, between 0.5 % (D. bracteata) and 47 % (D. magnifica) of the P supplied was transported to the plants (at rates between 0.001 and 0.097 fmol h-1). This experimental approach was capable of distinguishing species based on their P-foraging efficiency, and highlighted the role that fungi play in P nutrition during early seedling development. Our study shows that orchids occurring naturally on P-impoverished soils can obtain significant amounts of inorganic P from their mycorrhizal partners, and significantly more uptake of P supplied than previously shown in other green-leaved orchids. These results provide support for differences in mycorrhiza-mediated P acquisition between orchid species and fungal symbionts in green-leaved orchids at the seedling stage. The plant-fungus combinations of this study also provide evidence for plant-mediated niche differentiation occurring, with ecological implications in P-limited systems.

Axenic rhizome culture and genetic fidelity assessment of Eulophia dabia (D. Don) Hochr: an endangered terrestrial orchid species

Axenic rhizome culture and genetic fidelity assessment of Eulophia dabia (D. Don) Hochr: an endangered terrestrial orchid species

Structural characterization of Platanthera ussuriensis chloroplast genome and comparative analyses with other species of Orchidaceae

BackgroundThe genus Tulotis has been classified into the genus Platanthera in the present taxonomic studies since the morphological characteristics of this genus is very similar to that of Platanthera. Platanthera ussuriensis, formerly named as Tulotis ussuriensis, is a small terrestrial orchid species and has been listed as wild plant under State protection (category II) in China. An improved understanding of the genomic information will enable future applications of conservation strategy as well as phylogenetic studies for this rare orchid species. The objective of this research was to characterize and compare the chloroplast genome of P. ussuriensis with other closely related species of Orchidaceae.ResultsThe chloroplast genome sequence of P. ussuriensis is 155,016 bp in length, which included a pair of inverted repeats (IRs) of 26,548 bp that separated a large single copy (LSC) region of 83,984 bp and a small single copy (SSC) region of 17,936 bp. The annotation contained a total of 132 genes, including 86 protein-coding genes, 38 tRNA genes and 8 rRNA genes. The simple sequence repeat (SSR) analysis showed that there were 104 SSRs in the chloroplast genome of P. ussuriensis. RNA editing sites recognition indicated 72 RNA editing events occurred, and all codon changes were C to T conversions. Comparative genomics showed that the chloroplast sequence of Platanthera related species were relatively conserved, while there were still some high variation regions that could be used as molecular markers. Moreover, Platanthera related species showed similar IR/SSC and IR/LSC borders. The phylogenetic analysis suggested that P. ussuriensis had a closer evolutionary relationship with P. japonica followed by the remaining Platanthera species.ConclusionOrchidaceae is a key group of biodiversity protection and also a hot spot group in the plant taxonomy and evolution studies due to their characteristics of high specialization and rapid evolution. This research determined the complete chloroplast genome of P. ussuriensis for the first time, and compared the sequence with other closely related orchid species. These results provide a foundation for future genomic and molecular evolution of the Orchidaceae species, and provide insights into the development of conservation strategy for Platanthera species.

Spiranthinae (Orchidaceae - Cranichideae) from Uruguay: taxonomy and distribution

Uruguay occupies an area of special relevance for species of terrestrial orchids of the subtribe Spiranthinae because it is located in one of the largest continuous grassland regions of the Americas. The aim of this study is to provide a taxonomic study of Spiranthinae species from Uruguay. A total of 22 species distributed in seven genera were confirmed to the country, representing almost half of the species of terrestrial orchids in Uruguay. Cyclopogon (8 spp.), Skeptrostachys (5 spp.) and Brachystele (4 spp.) were the most representative. Additionally, a new synonym in Brachystele dilatata (=Brachystele waldemarii) is proposed. The group was found in all departments and ecoregions of the country, mainly in the southeastern (Maldonado: 10 spp., Rocha: 12 spp. Lavalleja: 10 spp.) and northeastern (Rivera: 11 spp., Tacuarembó 9 spp.) regions. Among the ecoregions, the “Serrano Forest” (17 spp.) and “Graben de la Laguna Merín” (14 spp.) were the most species-rich. Descriptions, illustrations, an identification key, and comments on geographical distribution of the species are provided.

Asymbiotic germination, initial development in vitro and acclimatization of Cyrtopodium paludicolum Hoehne, a Brazilian Savanna orchid species

Abstract Cyrtopodium paludicolum is a terrestrial orchid species, native to Brazil, whose natural propagation is jeopardized by the intensive collection from the wild and is threatened by agricultural expansion in Cerrado areas. In light of that, this investigation aimed at studying the in vitro germination and early development of C. paludicolum as influenced by culture medium, sucrose and growth regulators as well as its micropropagation by using dark-grown stem segments. A protocol for its acclimatization is also detailed. The effects of Murashige &amp; Skoog (MS), Knudson C (KC) and Vacin &amp; Went (VW) media on the in vitro germination and initial development were tested. The influence of different concentrations of BA, NAA, and of sucrose on plant multiplication and growth were evaluated. The possibility of using etiolated stem segments for micropropagation was also assessed. Acclimatization was accomplished in two phases by using three different substrates. The results showed that VW was the best medium for germination whereas for seedling formation KC was the most advantageous since they were healthy and vigorous. Sucrose at 2% favored the greatest seedling growth and development. Shoot and root proliferation and development were best promoted in the presence of 2.28/2.28 and 0.57/0.57 µM BA/NAA, respectively. The use of etiolated stem segments for micropropagation was effective. Successful acclimatization was accomplished by initially growing plants in community pots containing a 3:1 (v/v) mix of Bioplant and dried Sphagnum moss followed by their transfer to individual pots containing a 2:1 (v/v) mix of Bioplant and Ouro Negro substrates.

Native and alien poplar plantations are important habitats for terrestrial orchids

Poplar monocultures are some of the most common short-rotation coppices. While they are most often considered of low environmental value, they have recently gained recognition for their multifaceted role in ecological engineering, such as carbon sinks, soil remediators or green energy producers. Nonetheless, the biodiversity of poplar plantations remains little known and largely overlooked. Here we conducted a systematic botanical survey of 232 poplar plantations within the Pannonian ecoregion (central Europe) in order to assess their plant diversity, with particular focus on terrestrial orchids. Our results highlight that almost 60% of poplar monocultures harbour terrestrial orchids, some with several thousand specimens. Overall, we documented the occurrence of 15 species of terrestrial orchids in the surveyed plantations, including taxa with limited distributions and a threatened conservation status. For instance, we report numerous new populations of Epipactis bugacenis and E. tallosii in poplar plantations, suggesting that the majority of these taxa occur in poplar monocultures within Hungary. We analysed and highlight soil chemistry and plantation characteristics that predict the occurrence and species richness of terrestrial orchids in poplar monocultures. The probability of orchids being present is highest in older and larger poplar plantations, characterized by high total organic matter content and high soil pH. We conclude that plantations of native and alien poplar harbour valuable plant communities, including terrestrial orchids and other vascular plants of significant conservation importance. Using the knowledge generated here, we recommend delaying or partial harvest of poplar plantations to increase their conservation potential.