Online markets are becoming increasingly important for the trade of orchids. However, the sale of orchids online raises conservation concerns, as some sellers use these platforms to bypass regulations. In March 2024, we assessed the extent of trade of 28 nationally protected orchid species in the five most visited Indonesian-language online markets. Twenty-four of the 28 orchid species protected in Indonesia were being traded online, involving 1294 advertisements posted by 789 sellers. The majority (93%) of these sellers were located in Java; 3882 orchid individuals were sold during the performance of this research, with a total trade value of IDR 262 129 387 (USD 16 911). Furthermore, there were 2 831 688 orchid individuals reported to be available in stock by sellers, with a total potential trade value of more than IDR 231 billion (USD 14.9 million). None of the recorded sellers in the present study declared a permit for the orchids they offered. Our findings can be utilized by law enforcement agencies to identify key players and areas involved in this trade, as well as by conservationists and policymakers to determine which species are being traded and so might require further conservation measures.

Understanding the distribution and habitat requirements of species is crucial for designing conservation actions, yet this information is not available for many plant species. We report the first confirmed wild populations of Porroglossum parsonsii, which, because of its horticultural value, is commercialized in national and international markets, from where it was first described to science. Our large-scale survey of 341 10 × 30 m plots spanning Andean forests, paramo habitats and pasturelands in Colombia suggests that P. parsonsii has a restricted geographical distribution in Andean forests with high forest cover (71.4–86.2%), where it occurs in low numbers (5–17 individuals per plot). Because of its market value (USD 18–20 per plant) there is a risk the species could be collected illegally, and therefore the habitat of the species in the Santuario de Fauna y Flora de Iguaque requires appropriate conservation.

Tropical forest ecosystems are rich in epiphytes that make up a significant portion of the overall plant diversity. However, epiphytic plants are often understudied due to inaccessibility and the lack of basic ecological information poses challenges to their conservation, particularly in a time of rapid global change. The mule-ear orchid, Trichocentrum undulatum (Orchidaceae), is a large flowering epiphyte found in southern Florida (USA), the Greater, and Lesser Antilles including Cuba. The plant is Florida state-listed as endangered with only one remaining small and declining population in a coastal mangrove forest due to historical extraction and habitat destruction. Currently, there is no systematic understanding of the species’ habitat requirements. To fill this void, we compared the habitat and microhabitat of the species on its northern distribution edge (southern Florida) and the core range (in Cuba). The Florida population has only one host species, Conocarpus erectus, found in one habitat type. This is in sharp contrast to the 92 documented hosts and 5 habitats across 8 provinces in Cuba. Based on our findings from Cuba, we suggest conservation and restoration options in Florida by proposing potential suitable host plants and habitats. Proactive restoration of this species will help to ease the threat from sea-level rise to the species by securing and expanding range margins.

Many species are poorly known, with the sum of our knowledge represented by specimens in museums. For assessment of conservation status the most enigmatic and challenging species are probably those known only from a single specimen. We examine the potential persistence of such species using the orchid flora of Madagascar as a case study. We apply a statistical method that tests the likelihood of species presence in relation to the time when a species was collected and a measure of annual collection effort, calculated in three ways based on specimen collection over time. The results suggest that as of 2000 up to nine of the 236 orchid species known from a single specimen may be inferred to be extinct under at least one of the three methods of estimating collection effort and extinction. In addition, up to two additional species are likely to be extinct by 2018 assuming no new collections were made by that time. Substantial collection effort and/or additional evidence will be needed to reach a decision on the persistence of more recently observed species known only from a single collection. This represents a challenge for conservation practitioners.

Epiphytes are an important component of the diversity of tropical forests, and they also have several ecological functions. Vegetation heterogeneity is one of the features responsible for the high biodiversity of the Atlantic Forest, especially in the domain’s seasonal semideciduous forest (SSF). This biodiversity presents as high endemism and species richness. Owing to the seasonal nature of SSF, organisms that require high humidity (e.g. epiphytes) would be expected to show low species richness in these forests. The aims of this study were to conduct a survey of the vascular epiphytes in remnants of montane SSF in the Serra do Ibitipoca, Brazil, and to evaluate the importance of habitat heterogeneity for the richness and composition of species in these areas. We also evaluated whether the intrinsic characteristics of the SSF phytophysiognomy and fragmentation could result in low species richness and a high number of accidental epiphyte species. The study was conducted in the course of 18 expeditions undertaken between September 2013 and December 2016, covering five fragments of montane SSF (totalling 23.6 ha). We recorded 96 species (only one of which is an accidental epiphyte), distributed across 41 genera and 10 families. This is the highest epiphytic species richness recorded in Brazilian SSF to date. The results refuted the initial hypothesis and reinforce the importance to the epiphytic community of conservation of fragments with different structures.

Members of the orchid family occupy many germination niches, in terrestrial, epiphytic and epilithic environments. How orchid seeds attach to their substrate and survive after dispersal is largely unknown. C-lignin is a recently discovered specialized lignin, found in seed coats of some plants, including orchid species, but its functional and biological significance is obscure. We studied seed coat ontogenesis in three species (Neuwiedia veratrifolia, Cypripedium formosanum and Phalaenopsis aphrodite) that represent basal and advanced branches in orchid phylogeny and divergent life forms. From each species, controlled pollination yielded several stages of seed development, from which seed coats (testa) were isolated and analysed by ATR-FT-IR spectroscopy. The use of the ATR set-up ensured that the chemical information originated only from the integral outer seed surface layers. The FT-IR bands of C-lignin are presented here for the first time, and distinguished from bands of G/S-lignin. In the seed coats, C-lignin developed after G/S-lignin in N. veratrifolia and C. formosanum, while only G/S-lignin developed in P. aphrodite. We discuss C-lignin properties and possible function in relation to seed coat properties. The species differed with respect to sequence and amounts of deposition, not only of lignins but also lipids, resulting in differences in mature seed coat compositions. Thus we revealed an unexpected and marked diversity among orchids with respect to seed surface chemistry, with possible implications for seed and germination ecology.

The equitable sharing of benefits from natural resources is a key target of the Convention on Biological Diversity. Trade in its native species is one way in which a country can potentially benefit from its natural resources, and even small-scale traders can now access global markets online. However, little is known about the extent of benefit sharing for many products, and the extent to which the appropriate processes and permits are being used. We surveyed online trade in a lucrative and widely sold product in Southeast Asia (horticultural orchids) to assess the extent of access and benefit sharing. In total, 20.8% (n = 1120) of orchid species from the region were being sold. Although seven out of ten countries were trading, five had very little or no trade in their native species, and the majority of recently described endemic species being traded from non-range states had no reported Convention on the International Trade in Endangered Species of Wild Fauna and Flora exports from their country of origin. We suggest that addressing access and benefit-sharing gaps requires wider recognition of the problem, coupled with capacity building in the countries currently benefitting least: Laos, Myanmar and Cambodia. The priority should be to increase botanical capacity and enable these countries to better control the commercialization and trade of their native species.

Although it has long been acknowledged that seed characteristics are of major importance to the conquest of tree crowns by vascular epiphytes, there is surprisingly little quantitative evidence on the aerodynamic properties of their diaspores. We used a custom-built device to determine the terminal velocity (Vterm) of falling seeds, a parameter that has been shown to have high predictive power for the wind dispersal potential of diaspores under natural conditions. We determined Vterm of 45 species of epiphytic and terrestrial Orchidaceae, which almost doubles the currently available database for this family. Although varying by a factor of five with values of 0.09–0.4 m s−1, Vterm was invariably very slow compared to plants in general. For each species, we also took morphological data and determined seed mass. None of these parameters was linearly correlated with Vterm and neither did the average Vterm differ between species found in the two habitats, although seeds of terrestrial taxa were significantly larger and heavier. Finally, we demonstrate the potential of our device to measure Vterm of even smaller diaspores by successfully quantifying Vterm of fern spores. This tool has much potential for the quantitative study of dispersal of plants with tiny diaspores, particularly in a conservation context in fragmented landscapes.

Orchid seeds are among the smallest seeds in nature and they are naturally rich in fatty acids. However, the fatty acid composition of orchid seeds has not been investigated because the sample masses utilized for widely used methods for fatty acid profiling would generally require prohibitively large numbers (i.e. 10,000s) of seeds. The present work aimed to develop a method for fatty acid analysis using gas chromatography–mass spectrometry on small quantities (mg) of seeds. The method was developed using the seeds of two species, Dactylorhiza fuchsii, a temperate terrestrial, and Grammatophyllum speciosum, a tropical epiphyte. A range of sample masses was tested to determine the minimum mass required to achieve reliable fatty acid composition data. A direct transesterification method was used, which did not require extraction of fatty acids from seeds prior to analysis, and the effects of seed processing (crushed versus intact seeds) and incubation time in toluene on fatty acid yield were tested. Stable fatty acid profiles were obtained using as little as 10 mg of seeds. Neither crushing the seeds nor extending the toluene incubation step had much effect on the fatty acid yield. The simple direct transesterification method presented will enable the fatty acid composition of orchid seeds, and possibly other small seeds, to be determined reliably for studies into seed development, storage and germination.

Neottia dihangensis M.Bhaumik and N. confusa M.Bhaumik (Orchidaceae) from Arunachal Pradesh, India are described and illustrated.

Orchid species are well known for their highly specialized pollinator interactions. To better understand the reproductive biology of the tropical epiphytic orchid Bulbophyllum variegatum on Réunion, we investigated the floral morphology, breeding system, pollinator diversity, floral scent profile and fruiting success of about 30 individuals in three natural populations during two consecutive flowering seasons. Controlled hand-pollination experiments in two populations showed that the species is self-compatible, but requires pollinator service to achieve reproduction. Videotape pollinator observations were conducted during two flowering seasons for 56 h and revealed that B. variegatum is pollinated by a single species of fly from the Platystomatidae. This fly seems to be attracted by the unpleasant scent produced by the flowers, and does not receive any reward after achieving pollination. In addition, no egg-laying behaviour was observed. Bulbophyllum variegatum thus exhibits a typical sapromyiophilous pollination syndrome which constitutes the first proven case of sapromyiophily within the genus Bulbophyllum on the Mascarene Archipelago. Hand pollinations further showed that fruit set was not significantly higher for flowers that received outcross pollen than for those that were self-crossed (53% and 44% respectively). Fruit sets under natural conditions were significantly different among populations, ranging from 0.5% to 24.3%. This low fruit production is likely due to infrequent pollinator visits, particularly in disturbed forests where the pollinator has never been observed.

Appendicula nicobarica Jayanthi, Sumathi & Karthig. (Orchidaceae) is described and illustrated from Great Nicobar Biosphere Reserve, India.

Species interactions have been recently depicted as networks, in which each species is connected to one or more other species in binary interaction matrices. Forty networks of epiphytic orchid and host tree species were assessed in Brazilian gallery forests. The nestedness of the networks was estimated with the NODF index and the significance was tested with null models. The phylogenetic structure of the network was also assessed, by searching for phylogenetic signals in the number of interactions and in the similarity of interacting species. In total, 105 orchid species and 132 host tree species were sampled. A nested pattern in all orchid–host tree networks was found. However, phylogenetic signals were not observed. The results support that the host specificity of orchids is small and most of the interactions occur among generalist orchids and generalist host trees. While the concept of species-specificity can thus be rejected, the extreme alternative – that interacting orchids and host trees are not a random subset of the regional species pool – can be dismissed as well. However, factors other than phylogenetic history may structure interaction networks of epiphytic orchids and host trees.

Introduction. Mature green vanilla pods accumulate 4-O-(3-methoxy-benzaldehyde)-β-D-glucoside (glucovanillin), which, upon hydrolysis by an endogenous b-glucosidase, liberates vanillin, the major aroma component of vanilla. Little is known on the spatial distribution of aroma-generating phenolics, and the enzymes responsible for their liberation (β-glucosidase) and oxidation (peroxidase). We report here quantitative data with respect to these three components in relation to the anatomy of the pod. Furthermore, the spatial progression of oxidation is shown. Materials and methods. Mature green vanilla pods were analyzed for their contents of phenolics (HPLC), and β-glucosidase and peroxidase activities by spectrophotometric techniques using p-nitrophenyl glucoside and vanillin as substrates, respectively. Lipids were examined under fluorescence microscopy after Nile red staining. Oxidation development was observed on transverse slices of pods. Results and discussion. Phenolics, and β-glucosidase and peroxidase activities showed gradients of increasing-decreasing concentrations from the stem to the blossom end of pods. The β-glucosidase activity is distributed in between the placentae, mesocarp, and trichomes in a [7 / 2 / 1] proportion while that of peroxidase shows a [38 / 1] ratio in the mesocarp and placentae, and was absent from trichomes. Oxidation begins from the blossom end in the placentae, progressively invading the mesocarp and moving towards the stem end. Conclusion. The green mature vanilla pod is spatially heterogeneous for its phenolics, and β-glucosidase and peroxidase activities, its placentae playing an important role in the liberation of vanillin and its subsequent oxidation.

Almost 50% of the estimated 2500 species in the Bromeliaceae grow epiphytically in a remarkably wide range of habitats from inhospitable deserts to tropical rain forests (Benzing 2000). The degree of dependence on the host varies (Benzing 1990, Laube & Zotz 2006), and in some cases, epiphytic bromeliads may dispense completely with living hosts, and may thrive on artificial substrates such as electrical cables. This is not entirely surprising because this family provides examples of particularly remarkable adaptations to the epiphytic habitat like water-impounding leaf bases and water- and nutrient-absorbing scales (Benzing 2000). The so-called atmospheric forms in this family (e.g. Tillandsia recurvata) possess a dense covering of these scales, and use roots entirely as holdfasts, while leaves perform photosynthesis and take up water and nutrients. Although quite regularly mentioned in the literature (Benzing 1990, 2000; Brighigna et al. 1997, Lüttge 1989), we are not aware of any study investigating the vigour of plants growing on cables compared with plants growing on trees. The only functional aspects that have already been studied are related to nutrients, i.e. presence of nitrogen-fixing endophytes in Tillandsia recurvata plants from natural hosts and from electrical cables in Mexico (Puente & Bashan 1994) and differences in chemical composition of plant tissues and nutrient retention by leaves in Tillandsia capillaris growing on cables and trees in Argentina (Abril & Bucher 2009). Intermittent water supply, but also low nutrient supply, play an important role in epiphyte ecology (Zotz & Hietz 2001), which leads to the following alternative hypotheses: (1) Plants on electrical cables are usually close to roads.

The distribution of epiphytes differs between branches within tree crowns as well as within habitats. Where the original forests have been lost, shade coffee plantations can be important refuges for epiphytes, but are not suitable for all species. To understand what affects habitat quality, we transplanted 1440 seedlings each of two orchids, one, Lycaste aromatica, restricted to forests, the other, Jacquiniella teretifolia, common on trees in coffee plantations and in forests. Seedling mortality and growth were compared between three forests, three young and three old coffee plantations to test for differences between habitats and to analyse which habitat features affect growth and mortality. In J. teretifolia there was no clear pattern of habitat effect on mortality (c. 0.08 mo−1), but the production of new shoots was higher in coffee plantations than in forests. In L. aromatica, growth rates as well as seedling mortality increased over time. During the last census growth rates in forests (1.8 mm mo−1) were significantly higher than in old (0.9 mm mo−1) and young (1.2 mm mo−1) coffee plantations, and seedling mortality was about four times higher in old (0.10 mo−1) and young (0.11 mo−1) coffee plantations than in forests (0.025 mo−1), which may explain the natural absence of L. aromatica from coffee plantations. Mortality in L. aromatica at individual sites was negatively correlated with bryophyte cover on branches (Pearson r = –0.75) and positively with lichen cover (r = 0.70) and canopy openness (r = 0.75). Branch cover with non-vascular epiphytes, whether directly responsible by improving the water supply to epiphytes or indicative of differences in microclimate, may be a useful indicator of suitable habitats for vascular epiphytes.

The orchids Dendrobium infundibulum and Cymbidium insigne are pollinated by the bumblebee Bombus eximius, which also pollinates the ericaceous shrub Rhododendron lyi, A study of the three plants and the bumblebee in maquis-like mountainous vegetation in northern Thailand suggests that they form a floral mimicry system with two mimics (the orchids) to one model (R. lyi). The flowers of the two orchid species offer no food reward to pollinators. Flowers of the three species show definite morphological and visual resemblance, and the species overlap to a great extent in flowering phenology and habitat Mimic flowers were much less numerous than model flowers, which occurred abundantly in the area. The rate of pollinaria removal was very low in both orchid species, resulting in a relatively small percentage of fruit set, especially in D. infundibulum. Infrequency of pollinator visits was, however, somewhat counterbalanced by long-lasting flowers. The pollinaria of the two orchid species are differently positioned on the bee, hence interference between the different reproductive systems is minimized. This is the first report which indicates floral mimicry from tropical Asia.

Introduction. Mature green vanilla pods accumulate 4-O-(3-methoxy-benzaldehyde)-β-D-glucoside (glucovanillin), which, upon hydrolysis by an endogenous β-glucosidase, liberates vanillin, the major aroma component of vanilla. Sites of storage of glucovanillin in the pod have been controversially reported for decades; we aim, using precise and widely accepted technical terminology, to clarify this controversy by providing an anatomical, histochemical and biochemical evidence-based picture of glucovanillin accumulation sites. The pod also synthesizes an oleoresin and a mucilage of unknown constitutions; we report here their localization and structures. Materials and methods. The pod anatomy was examined by light and epifluorescence microscopy. A protocol was established allowing fine hand-dissection of diverse anatomical parts of the pod (mesocarp, placentae, trichomes, intralocular interstitial cell-free region and seeds). Glucovanillin and γ-pyranones were extracted and analyzed by HPLC, while the structures of the mucilaginous polysaccharides were determined after permethylation. Results and discussion. Glucovanillin is essentially stored in the placentae (92%) and marginally in trichomes (7%); traces were measured in the mesocarp and intralocular interstitial cell-free medium. Trichomes store massive amounts of a fluorescing oleoresin (44%) rich in alkenylmethyldihydro-γ-pyranones and synthesize a mucilage made of a glucomannan and a pectic polysaccharide carrying monomeric arabinose and galactose side-chains. Conclusion. To date, the physiological roles of glucovanillin, long-chain pyranones, and mucilage remain unknown.