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The plant kingdom exhibits a diversity of nutritional strategies, extending beyond complete autotrophy. In addition to full mycoheterotrophs and holoparasites, it is now recognized that a greater number of green plants than previously assumed use partly of fungal carbon. These are termed partial mycoheterotrophs or mixotrophs. Notably, some species exhibit a dependency on fungi exclusively during early ontogenetic stages, referred to as initial mycoheterotrophy. Japonolirion osense, a rare plant thriving in serpentinite soils, emerges as a potential candidate for initial mycoheterotrophy or mixotrophy. Several factors support this hypothesis, including its diminutive sizes of shoot and and seeds, the establishment of Paris-type arbuscular mycorrhizal associations, its placement within the Petrosaviales—largely composed of fully mycoheterotrophic species—and its ability to face the challenging conditions of its environment. To explore these possibilities, our study adopts a multidisciplinary approach, encompassing stable isotope abundance analyses, in vitro experiments, anatomical analyses, and comparative plastome analyses. Our study aims to (1) determine whether J. osense relies on fungal carbon during germination, indicating initial mycoheterotrophy, (2) determine if it employs a dual carbon acquisition strategy as an adult, and (3) investigate potential genomic reductions in photosynthetic capabilities. Contrary to expectations, our comprehensive findings strongly indicate that J. osense maintains complete autotrophy throughout its life cycle. This underscores the contrasting nutritional strategies evolved by species within the Petrosaviales. [ABSTRACT FROM AUTHOR]

Introduction: Tetrastigma hemsleyanum is a folk and rare medicinal plant, and specifically, it is distributed in the south, China. To investigate the cumulative properties of its medicinal components, we examined the effect of UV light on flavonoid content and related enzyme activity changes in T. hemsleyanum. Methods: The leaves and tubers were treated with UV-A, UV-B and UV-C for 1 h, 1L/23D h, 3 h and 3L/21D h (D represents darkness treatment). High-performance liquid chromatography (HPLC) analysis showed that the content of many flavonoids decreased significantly during UV-A treatment, increased after UV-B and UV-C irradiation and accumulated again after darkness treatment. Results: In the root tubers of the UV-A group, naringin content in the 3L/21D h group (0.069 μg/g) was 16.30 times higher than that of 3 h group (0.0042 μg/g). The rutin content was elevated after UV irradiation but was not detected in the CK group. The test results of the enzyme-linked kit indicated that the activities of many enzymes were higher in the UV-A and UV-B irradiation groups than those in the CK group, but the results were reversed in the UV-C treatment. After darkness treatment, the activities of most enzymes were higher than those with UV irradiation alone; F3'5'H activity in the 3L/21D h group (97.25 U/L) was 1.24 times higher than that in the 3 h group (78.12 U/L) in the UV-A-treated group. Discussion: The study results suggest that appropriate UV-B and UV-C irradiation, as well as darkness supplementation, had a promotive effect on flavonoids in the leaves and root tubers of T. hemsleyanum. Additionally, UV irradiation and darkness treatment enhanced the activity of most enzymes. [ABSTRACT FROM AUTHOR]

Background: Anemone shikokiana (Makino) Makino is a perennial herb of the genus Anemone in the family Ranunculaceae. Endemic to the Shandong Peninsula in China and Shikoku Island in Japan, it is a rare and endangered plant with a narrow, disjunct distribution. It is threatened with extinction and is in urgent need of conservation. Evaluating the genetic diversity of species, revealing the population genetic structure and gene flow, and inferring the population history are of great importance for species conservation, especially for rare and endangered plants. Results: In our study, 73 samples from eight wild populations in China were sequenced by Super-GBS, yielding a total of 40.59 G clean reads and 52,231 SNPs. Based on the obtained SNP data set, we evaluated the population genetic diversity, genetic structure, and gene flow of A. shikokiana. A low level of genetic diversity was found (He = 0.1925, Ho = 0.1422). The neighbor-joining (NJ) tree, principal component analysis and ADMIXTURE analysis suggested that these 73 A. shikokiana could be considered as two groups. Pairwise genetic differentiation coefficients (Fst) indicated that genetic differentiation was lower between adjacent populations and higher between geographically separated populations. The gene flow between Kunyu Mountain and Lao Mountain was very low. However, neither of the two regions showed evidence of Isolation by Distance. Conclusions: Here, we revealed the population genetic structure and gene flow of A. shikokiana from the Shandong Peninsula, China. This research provides valuable genetic resources for A. shikokiana and contributes to the scientific and effective conservation of the species. [ABSTRACT FROM AUTHOR]

Camellia luteoflora is a rare and endangered plant endemic to China. It has high ornamental and potential economic and medicinal value, and is an important germplasm resource of Camellia. To understand the distributions and differences in metabolites from different parts of C. luteoflora, in this study, we used liquid chromatography–tandem mass spectrometry (LC–MS/MS) to examine the types and contents of chemical constituents in five organs of C. luteoflora: roots, stems, leaves, flowers, and fruits. The results showed that a total of 815 metabolites were identified in the five organs and were classified into 18 main categories, including terpenoids (17.1%), amino acids (10.4%), flavonoids (10.3%), sugars and alcohols (9.8%), organic acids (9.0%), lipids (7.1%), polyphenols (4.8%), alkaloids (4.8%), etc. A total of 684 differentially expressed metabolites (DEMs) in five organs were obtained and annotated into 217 KEGG metabolic pathways, among which metabolic pathways, ABC transporters, the biosynthesis of cofactors, and the biosynthesis of amino acids were significantly enriched. In DEMs, flowers are rich in flavonoids, polyphenols, organic acids, and steroids; fruits are rich in amino acids, alkaloids, vitamins, and xanthones; stems are rich in lignans; and leaves have the highest relative content of phenylpropanoids, ketoaldehydic acids, quinones, sugars and alcohols, terpenoids, coumarins, lipids, and others; meanwhile, the metabolite content is lower in roots. Among the dominant DEMs, 58 were in roots, including arachidonic acid, lucidone, isoliquiritigenin, etc.; 75 were in flowers, including mannose, shikimic acid, d-gluconic acid, kaempferol, etc.; 45 were in the fruit, including pterostilbene, l-ascorbic acid, riboflavin, etc.; 27 were in the stems, including salicylic acid, d-(-)-quinic acid, mannitol, (-)-catechin gallate, etc.; there was a maximum number of 119 dominant metabolites in the leaves, including oleanolic acid, l-glucose, d-arabitol, eugenol, etc. In sum, the rich chemical composition of C. luteoflora and the significant differences in the relative contents of metabolites in different organs will provide theoretical references for the study of tea, flower tea, edible oil, nutraceuticals, and the medicinal components of C. luteoflora. [ABSTRACT FROM AUTHOR]

Elaeagnus bambusetorum Hand.-Mazz. is a rare plant from China in the Elaeagnaceae family. In this study, we sequenced its complete chloroplast genome. The whole chloroplast genome was 152,265 bp in length, containing a pair of inverted repeats of 25,897 bp, separated by large single copy and small single copy regions of 82,291 bp and 18,180 bp, respectively. The complete genome contained 113 genes, including 79 protein-coding genes, 30 tRNA genes, and 4 rRNA genes. The overall GC content was 37.1%. Phylogenetic analysis using the whole chloroplast genome revealed that E. bambusetorum is sister to E. loureirii and E. conferta. Our study provides valuable insights into the genetic information of E. bambusetorum, which may have important implications for species conservation. [ABSTRACT FROM AUTHOR]

The tropical Garcinia genus of flowering plants is a prolific producer of aromatic natural products including polyphenols, flavonoids, and xanthones. In this study, we report the first phytochemical investigation of Garcinia caudiculata Ridl. from the island of Borneo. Fractionation, purification, and structure elucidation by MS and NMR resulted in the discovery of two meroterpenoids. One was a benzofuranone lactone previously isolated from Iryanthera grandis and Rhus chinensis, and the second was a new hydroquinone methyl ester that we named caudiquinol. Both natural products are rare examples of plant meroterpenoids with an intact geranylgeranyl chain. [ABSTRACT FROM AUTHOR]

Public lands across the United States are managed for multiple uses, resources, and values ranging from energy development to rare plant conservation. Intensified energy development and other land use changes across the Southwestern United States have increased the need for proactive management to mitigate impacts to rare plants. Habitat suitability models can inform decision‐making and lead to more effective conservation of rare plants and their habitats, but high‐quality models that are suited for use at local scales are lacking for many species. Our team of scientists and managers developed ensembles of habitat suitability models for five rare plant species in New Mexico using a coproduced, iterative framework complemented by comprehensive ground truthing and tailoring of products for use in public land decisions. Our process resulted in substantial differences from initial models through changes to environmental predictors, species occurrence and background data, and development of new species‐specific predictors. Involving species experts and end users in model development can strengthen the process and resulting model and build understanding and trust in final products. Both factors can promote use of models to inform public land permitting and planning decisions that may affect rare plants, including by guiding development away from highly suitable habitats. [ABSTRACT FROM AUTHOR]

The river valley forests of the Irtysh River Basin are a germplasm bank of Salicaceae species and rare plant resources in China, and the distribution varies with the river and is highly distinctive. However, there is a dearth of systematic research on the characteristics of plant resources. In this study, a comprehensive investigation was conducted in the trunk stream and six tributaries with valley forest distribution in the Irtysh River Basin, and 244 quadrats were set up. The analysis focused on the composition of the flora and resource characteristics. The results reveal the following: (1) The valley forests of the Irtysh River Basin contain 256 species of plants belonging to 57 families and 178 genera, among which 19 species of trees, 23 species of shrubs, and 214 species of herbs were investigated. (2) Among the identified species, 226 (88.67%) were recognized as resource plants, with medicinal plants being the most abundant (176 species, 68.75% of the total). (3) The distribution patterns of trees, shrubs, and herbs of each resource type vary across rivers. Elevation drop, river length, and river distance all significantly affect the number of specie. This study elucidated the current status and distributional characteristics of plant resources in the valley forests of the Irtysh River Basin, which is essential for both biodiversity conservation and sustainable resource utilization. [ABSTRACT FROM AUTHOR]

The rare and endangered plant species Abies fanjingshanensis, which has a limited habitat, a limited distribution area, and a small population, is under severe threat, particularly due to poor leaf health. The plant endophytic microbiome is an integral part of the host, and increasing evidence indicates that the interplay between plants and endophytic microbes is a key determinant for sustaining plant fitness. However, little attention has been given to the differences in the endophytic microbial community structure, network complexity, and assembly processes in leaves with different leaf health statuses. Here, we investigated the endophytic bacterial and fungal communities in healthy leaves (HLs) and non-healthy leaves (NLs) of A. fanjingshanensis using 16S rRNA gene and internal transcribed spacer sequencing and evaluated how leaf health status affects the co-occurrence patterns and assembly processes of leaf endophytic microbial communities based on the co-occurrence networks, the niche breadth index, a neutral community model, and C-score metrics. HLs had significantly greater endophytic bacterial and fungal abundance and diversity than NLs, and there were significant differences in the endophytic microbial communities between HLs and NLs. Leaf-health-sensitive endophytic microbes were taxonomically diverse and were mainly grouped into four ecological clusters according to leaf health status. Poor leaf health reduced the complexity of the endophytic bacterial and fungal community networks, as reflected by a decrease in network nodes and edges and an increase in degrees of betweenness and assortativity. The stochastic processes of endophytic bacterial and fungal community assembly were weakened, and the deterministic processes became more important with declining leaf health. These results have important implications for understanding the ecological patterns and interactions of endophytic microbial communities in response to changing leaf health status and provide opportunities for further studies on exploiting plant endophytic microbes to conserve this endangered Abies species. [ABSTRACT FROM AUTHOR]

The reproduction of rare and endangered plant species is one of the most important factors determining the stability and survival of their populations, and knowledge of the barriers to successful reproduction is essential for species conservation. Habitat loss and slow reproduction due to low fruit set are usually considered the main threats to Cephalanthera longifolia and C. rubra (Orchidaceae). The aim of this study was to analyse the natural fruit set of these species during three consecutive years in Lithuania in the northern part of the temperate zone of Europe. Six populations of C. longifolia and three populations of C. rubra were studied each year from 2021 to 2023. During the study period, 49.3% to 54.4% of C. longifolia and 40.0% to 54.3% of C. rubra individuals produced no fruit. Over the three-year period, fruit set in individual populations of C. longifolia ranged from 5.2% to 19.5%, whereas fruit set in populations of C. rubra ranged from 4.1% to 18.8%. Significant weak or moderate correlations were found between plant height, inflorescence length and the number of flowers in the inflorescence and fruit set of both species. Flower position in the inflorescence had a significant effect on fruit set in both species, and the fruit set rate of lower flowers was higher than that of upper flowers. Significant but weak correlations were found between the fruit set and most of the environmental factors analysed. The results of this study suggest that the fruit set of C. longifolia and C. rubra is dependent on insect pollination of the flowers, which in turn is affected by habitat conditions. [ABSTRACT FROM AUTHOR]

Public lands are often managed for multiple uses ranging from energy development to rare plant conservation. Habitat models can help land managers assess and mitigate potential effects of projects on rare plants, but it is unclear how models are currently being used. Our goal was to better understand how staff in the Bureau of Land Management currently use habitat models to inform their decisions, and perceived challenges and benefits associated with that use. We first examined litigation documents to determine whether the agency has been challenged on its use of data for rare plants and found no relevant legal challenges. Second, we analyzed model use in National Environmental Policy Act (NEPA) documents and found no clear citations of habitat models. Finally, we conducted interviews with agency staff who analyze potential effects of proposed actions on rare plants in NEPA documents. The primary challenges interviewees faced in using models related to data organization and access, model quality and accuracy, and institutional capacity. Interviewees believed models could be used more to inform decisions and actions to conserve rare plants and rare plant habitat on public lands and recommended improving staff access to models, creating models for additional species, and addressing staffing limitations. [ABSTRACT FROM AUTHOR]

In this study, we assembled high-quality chloroplast genomes of Mandragora caulescens through a reference-guided approach using high-throughput Illumina sequencing reads. The resulting chloroplast genome assembly displayed a typical quadripartite structural organization, comprising a large single-copy (LSC) region of 85,233 bp, two inverted repeat (IR) regions of 25,685 bp each, and a small single-copy (SSC) region of 18,207 bp. The chloroplast genome harbored 141 complete genes, and its overall GC content was 38.0%. In maximum-likelihood (ML) and Bayesian inference (BI) trees, the 19 Solanaceae species formed a monophyletic group, dividing into two main clades. M. caulescens and Nicandra physalodes formed a monophyletic group, suggesting a close relationship between the two species. The M. caulescens cp genome presented in this study lays a good foundation for further genetic and genomic studies of the Solanaceae. [ABSTRACT FROM AUTHOR]

Nymphoides coronata is an endangered aquatic plant species with significant medicinal and ecological importance. To preserve N. coronata from going extinct, we need to provide seedlings and efficient multiplication techniques so that it can be extensively studied. This study aimed to identify the most suitable sterilization treatment, growth medium, and substrate for the cultivation and propagation of N. coronata. Ethanol sterilization, fungicide treatment, and sterile water washing were the most important sterilization steps. A combination of 6-benzylaminopurine (6-BA) and indoleacetic acid (IAA) was the most suitable medium for bud induction and shoot proliferation. The use of α-naphthaleneacetic acid (NAA) increased the rooting rate and rooting time compared to indole-3-butyric acid (IBA). Increasing the concentration of NAA from 0.5 to 1.0 mg/L increased the rooting rate from 78 to 100% and reduced the rooting time from 7 to 5 days. The survival rate of N. coronata seedlings was 100% in a mixture of red soil and sand (1:1, w/w). As a result, the procedure mentioned above could potentially be used to safely propagate this rare species on a large scale. These findings provide valuable insights into the optimal conditions for the successful cultivation and propagation of N. coronata, which can contribute to the conservation and sustainable use of this important rare plant species. [ABSTRACT FROM AUTHOR]

Background. Comparison of ontogenetic indicators of local populations of the yellow flax plant Linum flavum L., rare for the Penza region, was aimed at assessing their current state as the basis for further monitoring and development of measures to protect the species to preserve the biodiversity of the Penza region. Materials and methods. Under the conditions of the protection regime (the natural monument “Urochische Cherdak”) and in the conditions of the restoration of steppe communities on fallow land (the Ukhtinsky steppes tract), the density, numbers, and ontogenetic structure of local populations of yellow flax were studied, as well as the phytocenotic location of the species and its contribution to the structure of communities at different stages restorative succession. Results. In the studied communities of true and meadow steppes, steppe and true meadows, Linum flavum forms a caudex facultative- root-sprouting biomorph. Shows traits of explerence. When the vegetation cover is highly dense, it acts as an assectator with a projective cover of 2–4 %; populations have a low density (2.5 pcs/m2). In disturbed communities it dominates and co-dominates (projective cover 20–25%), increasing the density by an order of magnitude due to individuals of the pregenerative period. Ontogenetic spectra in both cases are two-peaked – with a maximum in juvenile and generative individuals; in weakly disturbed communities, the main contribution to the structure is made by mature and old generative individuals, and in fallows – by juvenile individuals (populations according to the “Δ – ω” classification are transitional and young, respectively). Conclusions. The current state of both local populations is stable. To preserve the population of Linum flavum and other rare species (Salvia verticillata, Senecio schvetzovii, Aster amellus, Gypsophila altissima) in the vicinity of the village. In Ukhtinka village it is rational to limit economic activity by organizing the natural monument “Ukhtinskiye stepi”.

In Bangladesh, there are significant number of medicinal plants, but currently no comprehensive record of these valuable species is publicly available. Alarmingly, some of these plants are in a precarious state of endangerment. Therefore, we are creating a unique dataset of Bangladeshʼs rare, endangered, and threatened medicinal plants to support conservation efforts. It will help us to track and conserve endangered plant species, ensuring a more organized approach to research and preservation efforts. We conducted on-site visits to the National Botanical Garden and The Government Unani and Ayurvedic Medical College, capturing photographs of these plants in optimal sunlight conditions at various times of the day. This involved fieldwork, detailed image annotations, dataset organization, diversity augmentation, and contribution to the preservation of our natural heritage. We have collected a total of 16 types of rare and endangered medicinal plant leaf photos to create our unique dataset consisting of a total of 3494 images. This dataset will help researchers in biodiversity conservation through building efficient machine learning models and applying advanced machine learning techniques to identify rare and endangered medicinal plants.

Rare species are often considered inferior competitors due to occupancy of small ranges, specific habitats, and small local populations. However, the phylogenetic relatedness and rarity level (level 1–7 and common) of interacting species in plant-plant interactions are not often considered when predicting the response of rare plants in a biotic context. We used a common garden of 25 species of Tasmanian Eucalyptus, to differentiate non-additive patterns in the biomass of rare versus common species when grown in mixtures varying in phylogenetic relatedness and rarity. We demonstrate that rare species maintain progressively positive non-additive responses in biomass when interacting with phylogenetically intermediate, less rare and common species. This trend is not reflected in common species that out-performed in monocultures compared to mixtures. These results offer predictability as to how rare species' productivity will respond within various plant-plant interactions. However, species-specific interactions, such as those involving E. globulus, yielded a 97% increase in biomass compared to other species-specific interaction outcomes. These results are important because they suggest that plant rarity may also be shaped by biotic interactions, in addition to the known environmental and population factors normally used to describe rarity. Rare species may utilize potentially facilitative interactions with phylogenetically intermediate and common species to escape the effects of limiting similarity. Biotically mediated increases in rare plant biomass may have subsequent effects on the competitive ability and geographic occurrence of rare species, allowing rare species to persist at low abundance across plant communities. Through the consideration of species rarity and evolutionary history, we can more accurately predict plant-plant interaction dynamics to preserve unique ecosystem functions and fundamentally challenge what it means to be "rare". [ABSTRACT FROM AUTHOR]

Premise: Reintroductions or translocations are an increasingly important activity to recover and conserve at‐risk plant species. Yet because many are not published in the scientific literature, learning from previous attempts may often require considerable time and effort. The Center for Plant Conservation Reintroduction Database (CPCRD; https://saveplants.org/reintroduction-database/), a new centralized and standardized repository of U.S.‐based plant reintroductions, aims to improve the efficiency and effectiveness of accessing data on rare plant reintroductions. Methods: The CPCRD is the product of multiple efforts to assemble information on rare plant reintroductions in the United States. The database comprises a wealth of standardized data on the key stages of a reintroduction, from the planning and implementation phases, to monitoring and management techniques. Results: The CPCRD is a dynamic resource, allowing data contributors to continually update their entries as projects progress. While contributions are ongoing, the CPCRD currently includes 460 projects involving 201 plant taxa, spanning diverse growth forms, ecosystems, and regions. Discussion: The CPCRD and its well‐documented and monitored projects provide a valuable practical resource for conservation practitioners, and have supported multiple scientific studies and contributed to the internationally recognized Center for Plant Conservation Best Practices Guidelines. [ABSTRACT FROM AUTHOR]

This study investigates the host diversity and characteristics of the rare parasitic plant Silverberry-like taxillus (Taxillus yadoriki). Seogwipo, Jeju Island, where T. yadoriki grows naturally, was examined to clarify the diversity of host species, their location, and the part of the tree where T. yadoriki is attached. A total of 687 host trees were found. Taxillus yadoriki was intensively distributed in the lowlands below 200 m a.s.l. The host trees belonged to 40 species, four varieties, three cultivars, and two hybrids from 32 genera and 21 families, of which 23 taxa were identified as host plants for the first time in this study. Incredibly, this plant was found to be able to parasitize a variety of plants from 12 orders. Taxillus yadoriki was found to be parasitic in three orders of Gymnosperms, Ginkgoales, Cupressales, and Pinales, as well as nine orders of Angiosperms, including Magnoliales, Rosales, and Ericales. Rosaceae was the most diverse at 18.0%, and most species were broad-leaved and arboreal. Among them, Cryptomeria japonica and Litsea japonica had the highest frequency of parasitization and T. yadoriki was mainly attached to the upper part of the main tree and the main branch; as a result, T. yadoriki was distributed and showed specificity in the position of disturbance on the host. T. yadoriki's specific distribution model was built as a Maxent program. The area under the curve of the receiver operation characteristic was 0.948 ± 0.026 (mean ± standard deviation), and the performance of the constructed model was excellent. Of the total eight environmental factors, density of artistic forest and meant temperature of coldest quarter accounted for 75.3% of the total importance, which was the main distribution determinant of species. In the average distribution probability map of T. yadoriki, the critical probability for determining distribution was calculated to be 0.2898 ± 0.1018. Accordingly, the distribution of species is predicted to expand from Jeju Island to the entire southern and southeastern coasts. [ABSTRACT FROM AUTHOR]

The genus Alstonia belonging to the Apocyanaceae family is represented by 44 species distributed worldwide. In India, the taxon is represented by eight species, reported from Andaman & Nicobar Islands, Western Ghats, Eastern Ghats, western Himalaya, and northeastern regions. The present study reported the occurrence of Alstonia sebusii from Pudunamei village, Mao, a new addition to the flora of Manipur. Detailed morphological descriptions and measurements were recorded based on living plant specimens. The plant is locally called 'Topfiira Koso Pro' having ethno-medicinal properties and widely been used by local people of the state to treat various ailments. The plant is rare and found to occur at specific location at Pudunamei village. [ABSTRACT FROM AUTHOR]

The fundamental goal of a rare plant translocation is to create self‐sustaining populations with the evolutionary resilience to persist in the long term. Yet, most plant translocation syntheses focus on a few factors influencing short‐term benchmarks of success (e.g., survival and reproduction). Short‐term benchmarks can be misleading when trying to infer future growth and viability because the factors that promote establishment may differ from those required for long‐term persistence. We assembled a large (n = 275) and broadly representative data set of well‐documented and monitored (7.9 years on average) at‐risk plant translocations to identify the most important site attributes, management techniques, and species' traits for six life‐cycle benchmarks and population metrics of translocation success. We used the random forest algorithm to quantify the relative importance of 29 predictor variables for each metric of success. Drivers of translocation outcomes varied across time frames and success metrics. Management techniques had the greatest relative influence on the attainment of life‐cycle benchmarks and short‐term population trends, whereas site attributes and species' traits were more important for population persistence and long‐term trends. Specifically, large founder sizes increased the potential for reproduction and recruitment into the next generation, whereas declining habitat quality and the outplanting of species with low seed production led to increased extinction risks and a reduction in potential reproductive output in the long‐term, respectively. We also detected novel interactions between some of the most important drivers, such as an increased probability of next‐generation recruitment in species with greater seed production rates, but only when coupled with large founder sizes. Because most significant barriers to plant translocation success can be overcome by improving techniques or resolving site‐level issues through early intervention and management, we suggest that by combining long‐term monitoring with adaptive management, translocation programs can enhance the prospects of achieving long‐term success. [ABSTRACT FROM AUTHOR]

Lack of ecological knowledge is a major challenge for effective conservation of threatened plant species in Australia as disturbance events, such as wildfire, increase in frequency and magnitude. Rapid on‐ground surveys are increasingly important to inform recovery strategies for rare and threatened plants in response to extreme wildfire events, yet resources are rarely available to deploy time‐sensitive surveys. Here, we utilize a rapid on‐ground survey and monitoring program to document basic biological and ecological information for 21 rare and threatened plant species from the New England bioregion in northern New South Wales, which were affected by the catastrophic 2019–2020 megafires. Our results fill an important knowledge gap of ecology, population size, distribution and response to fire for these taxa, document for the first time a species distribution pattern within the Torrington State Conservation Area and reveal previously undocumented plant–insect interactions for nine species, including likely pollination of Persoonia terminalis ssp. terminalis and Monotaxis macrophylla by native bee (Hymenoptera) and fly (Diptera) species. Our findings reveal that two species (Cassinia heleniae and Hakea macrorrhyncha) have scarce distribution and low population sizes, despite neither having a conservation listing and their threat status should be urgently assessed. Simple rapid on‐ground surveys can be more cost effective for delivering long‐term conservation outcomes for rare and threatened taxa and we advocate that future funding and prioritisation processes must support the immediate delivery of such surveys in response to disturbance events. [ABSTRACT FROM AUTHOR]

Multi‐year and multi‐site demographic data for rare plants allow researchers to observe threats and project population growth rates and thus long‐term persistence of the species, generating knowledge, which allows for effective conservation planning. Demographic studies across more than a decade are extremely rare but allow for the effects of threats to be observed and assessed within the context of interannual environmental variation. We collected demographic data on the Threatened plant Cirsium pitcheri in two sites from 2011–2022. These sites were chosen because one exhibited the presence of non‐native seed predators while the other did not, and we hypothesized that we would see declines and potentially extinction of the population threatened by predation. Over the course of our study, we observed additional threats, such as human trampling and high lake levels, which led to significant erosion, sand burial, and storm damage to plants. We find high interannual variation in vital rates and population growth rates for both populations, which mask the overall effects of predation. We observed dramatic declines in plant survivorship and population growth rates in both sites in the years with high lake levels. We conclude that high lake levels, which are expected to become more frequent with climate change, pose a significant threat to all near‐shore populations of C. pitcheri. [ABSTRACT FROM AUTHOR]

Neuwiedia singapureana is a rare and endangered plant of the Apostasioideae subfamily. The Apostasioideae subfamily has a unique evolutionary status, as it is considered to be the most primitive group forming the base of the Orchidaceae evolutionary tree. Therefore, N. singapureana has high scientific research and conservation value. The endophytic fungal communities associated with orchids are rich and diverse, but few studies have investigated the endophytic fungi of Neuwiedia orchid plants. In the present study, the aim was to examine the endophytic fungal community structures associated with wild N. singapureana rhizomes and normal roots in the ground and with bare prop roots in the air at two sampling sites in China. High-throughput sequencing of nuclear ribosomal DNA fragments of the internal transcribed spacer regions was conducted, and cultivable methods were adopted. A total of 2161 endophytic fungal operational taxonomic units (OTUs) were obtained at a 97% sequence similarity threshold. The endophytic fungal diversity differed among the samples but not significantly. There were many more non-mycorrhizal endophytic fungal than orchid mycorrhizal (OM) fungal species detected in the N. singapureana orchid, about 98.33% OTUs of non-mycorrhizal fungi contrasting with 1.67% OTUs of potential orchid mycorrhizal fungi, among which Ceratobasidiaceae, Russulaceae, and Thelephoraceae were the dominant orchid mycorrhizal fungi. One culturable OM fungal Epulorhiza sp. isolated from the rhizome was capable of significantly promoting the seed germination and seedling growth of Dendrobium officinale and Epidendrum secundum orchids, respectively, with different efficiencies. These endophytic fungal strains with growth-promoting functions will provide materials for orchid conservation and for the study of the mechanisms underlying orchid symbiotic associations. [ABSTRACT FROM AUTHOR]

The decline in seedling growth of Malania oleifera as the age increases is often observed in the absence of host plants. A better knowledge of nutrient dynamics in terms of concentration and distribution patterns in different parts of the declining seedlings, the concentrations of N, P, and K were comparatively analyzed in various organs of unattached M. oleifera seedlings grown for half a year, two years, and three years. Additionally, the starch content and distribution patterns in the roots and stems of seedlings with different vigor levels were qualitatively assessed by staining cross-sections. The results were as follows:(1)As the growth vigor of M. oleifera seedlings declined, the concentrations of N, P, and K in most organs decreased, except for a significant increase in K concentration in lateral roots. The leaf N/P ratios of the declining seedlings became increasingly imbalanced, indicating different nutrient deficiency types among the seedlings with varying decline degrees. Unattached M. oleifera seedlings grown for half a year were primarily limited by insufficient N supply(with an average N/P ratio of 11.33)and subsequently by P limitation after two years(average N/P ratio 17.81). The leaf N/P ratio of unattached M. oleifera seedlings grown for three years was remarkably imbalanced(with an average value of 52.46). As the growth vigor of unattached three-year seedlings was considerably low, they are deemed unsuitable for afforestation.(2)A decrease in starch content was observed in declining seedlings, as evidenced by the reduced staining intensity of cross-sections. After three years, the starch content of unattached M. oleifera seedlings was found to have decreased to an extremely low level. Significant differences in starch content were observed at various locations, including the connecting point of the stems and roots, the basal swelling top of the root, the main root, and lateral roots, among seedlings with different degrees of decline. These findings suggested that starch content levels could serve as crucial criteria for evaluating the growth vigor of seedlings. Specifically, lateral roots were identified as optimal sampling materials for assessing seedling growth vigor through a minimally invasive method. Given the gradual decline in vitality and decreased nutrient content observed in M. oleifera seedlings grown in the absence of a host plant, it is recommended, during the propagation phase, to ensure adequate mineral nutrient supplementation, select appropriate host plants for cultivation, and facilitate early-stage transplantation. This proactive approach serves to mitigate a potential decline in survival rates during afforestation, attributed to the reduced vitality of the seedlings. The results of this study provide valuable information for evaluating seedling growth vigor and offer scientific guidance for rational fertilization in M. oleifera nurseries. [ABSTRACT FROM AUTHOR]

Premise: Rafflesia are rare holoparasitic plants. In the Philippines, all but one species are found only on single islands. This study aimed to better understand the factors contributing to this distributional pattern. Specifically, we sought to determine whether narrow environmental tolerances of host and/or parasite species might explain their island endemicity. Methods: We used Maxent species distribution modeling to identify areas with suitable habitat for R. lagascae, R. lobata, and R. speciosa and their Tetrastigma host species. These analyses were carried out for current climate conditions and two future climate change scenarios. Results: Although species distribution models indicated suitable environmental conditions for the Tetrastigma host species in many parts of the Philippines, considerably fewer areas were inferred to have suitable conditions for the three Rafflesia species. Some of these areas are on islands from which they have not been reported. All three species will face significant threats as a result of climate change. Conclusions: Our results suggest that limited inter‐island dispersibility and/or specific environmental requirements are likely responsible for the current pattern of island endemicity of the three Rafflesia species, rather than environmental requirements of their Tetrastigma host species. [ABSTRACT FROM AUTHOR]

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Background: Dioecy, a sexual system of single-sexual (gynoecious/androecious) individuals, is rare in flowering plants. This rarity may be a result of the frequent transition from dioecy into systems with co-sexual individuals. Results: In this study, co-sexual expression (monoecy and hermaphroditic development), previously thought to be polyploid-specific in Diospyros species, was identified in the diploid D. oleifeara historically. We characterized potential genetic mechanisms that underlie the dissolution of dioecy to monoecy and andro(gyno)monoecy, based on multiscale genome-wide investigations of 150 accessions of Diospyros oleifera. We found all co-sexual plants, including monoecious and andro(gyno)monoecious individuals, possessed the male determinant gene OGI, implying the presence of genetic factors controlling gynoecia development in genetically male D. oleifera. Importantly, discrepancies in the OGI/MeGI module were found in diploid monoecious D. oleifera compared with polyploid monoecious D. kaki, including no Kali insertion on the promoter of OGI, no different abundance of smRNAs targeting MeGI (a counterpart of OGI), and no different expression of MeGI between female and male floral buds. On the contrary, in both single- and co-sexual plants, female function was expressed in the presence of a genome-wide decrease in methylation levels, along with sexually distinct regulatory networks of smRNAs and their targets. Furthermore, a genome-wide association study (GWAS) identified a genomic region and a DUF247 gene cluster strongly associated with the monoecious phenotype and several regions that may contribute to andromonoecy. Conclusions: Collectively, our findings demonstrate stable breakdown of the dioecious system in D. oleifera, presumably also a result of genomic features of the Y-linked region. [ABSTRACT FROM AUTHOR]

Podzol soils (Podzol) sampled in the area affected by the rare metal plant in the Murmansk oblast were analyzed using the inductively coupled plasma mass spectrometry to determine the bulk content of 14 rare earth elements (REEs) and the contents of their water-soluble, exchangeable, and mobile species. The mean bulk content of ΣREE in the soil sampled near tailings amounts to 594.9 mg/kg (218.2–1177.6 mg/kg), which is considerably higher as compared with the conventionally background soil (90.4 mg/kg, 79.45–101.35 mg/kg). The contents of individual REEs in the examined soils follow those in the mill tailings of loparite ores, thereby confirming the impact of mining activities on the content and distribution of REEs. The calculated REE enrichment factors (EFs) for soils vary from insignificant (EFΣREE = 2.4) to high (EFΣREE = 13.0). High EF values coincide with wind directions, suggesting an airborne technogenic nature of soil pollution caused by the dusting of tailings. [ABSTRACT FROM AUTHOR]

The screening of rare plants from the Yucatan region and the known native plants in Mexico, that have been successfully introduced worldwide, has been conducted. Based on a literature analysis and a search of English and Spanish scientific information regarding botanical, plant biochemical, and antioxidant potential in databases such as Google Scholar, Scopus, Web of Knowledge, as well as the national databases of Mexico (Flora: Yucatan Peninsula (cicy.mx) and Especies endémicas|Biodiversidad Mexicana), rare or underutilized plants from the Yucatan region with antioxidant potential have been selected. The formulas of the most studied secondary metabolites of these selected rare plants are shown. Among the selected rare plants with antioxidant potential, the families Sapidaceae and Anacardiaceae had the highest number of representatives. Additionally, representatives from the families Annonaceae, Moraceae, Malpighiaceae, Solanaceae, Ebenaceae, Asteraceae, Ranunculaceae, and Leguminosae were also presented. The current scientific data analysis of selected rare plants from the Yucatan region, Mexico, provides significant background for their further use and introduction in not only the Yucatan region of Mexico, but also worldwide. [ABSTRACT FROM AUTHOR]

Arid tropical archipelagos, such as the Galapagos Islands, host a high concentration of endemic plant species, many of which require restoration intervention to recover from past environmental degradation. Water-saving technologies (WSTs) have potential for hastening restoration by providing plants with additional water during the early stages of growth. However, it remains unclear whether such technologies provide an advantage for plant species of arid-tropical regions. This study examined the effect of the water-saving technology Groasis Waterboxx®(Groasis) on the rare endemic plant species Scalesia affinis ssp. brachyloba during early stages of restoration. Survival was monitored for 374 individuals planted across six sites on Santa Cruz Island, Galapagos (326 with technology and 48 as controls). Kaplan-Meier survival analysis showed that the use of Groasis reduced mortality during the first two years of the seedling survival. A mixed-effect logistic regression that modelled plant survival as a function of total precipitation, maximum temperature, and WST treatment (Groasis and notechnology control) found that despite low overall survival rates, plants grown with Groasis exhibited a three-fold higher predicted survival by the end of the 3.7 year duration of the study. Finally, through a resampling method, we demonstrate that the effect of the WST treatment is not dependent on the unbalanced design typical of a restoration project framework. We conclude that water-saving technologies such as the Groasis Waterboxx® can enhance survival of rare plant species such as S. affinis ssp. brachyloba in restoration programs in arid-tropical regions. [ABSTRACT FROM AUTHOR]

The genus Phagnalon Cass. (Asteraceae) is composed of widely distributed species and most of them, due to the medicinal properties they possess, are widely used in folk medicine but also as spices in the culinary field. The polar and non-polar extracts, as well as the complex mixtures of their essential oils, from several Phagnalon species and ssp., have shown antibiotic, antiviral, cytotoxic, and several other biological properties. In this work, the chemical composition and the antimicrobial, cytotoxic, and antioxidant properties of the Jordan accession of Phagnalon sinaicum Bornm. & Kneuck. essential oil (EO), an extremely rare plant that grows in ravines in the Middle East, were investigated. The EO, analyzed by GC-MS, was found to be rich in terpenoid compounds, and, in particular, in oxygenated monoterpenes, with the main compound being artemisia ketone (22.3%), followed by α-thujone (17.7%), and santolin alcohol (14.8%). The EO had good antimicrobial activity, especially against Escherichia coli Gram-negative bacterium (3 mg/mL MIC values) and was also effective in counteracting in vitro biofilm formation. Furthermore, this EO showed low cytotoxicity against immortalized human keratinocytes lines, but had good antioxidant activity on the same eukaryotic cellular models. [ABSTRACT FROM AUTHOR]

Morphometric techniques are crucial when studying rare plant species as they provide a comprehensive dataset on individual plants and the status of specific populations under various ecological conditions and different levels of human impact. Linaria cretacea, an endemic plant species, is listed as rare and can be found exclusively in the chalk hills in North-Western Kazakhstan (NWK). Over the span of 2020 to 2022, we conducted a study on four populations of this species located in the chalk hills in NWK. Through the process of inventorying sampling plots, we assessed the elevation range occupied by the species, while also identifying the age structure and population density. The results of our study provided further evidence of the limited population counts of Linaria cretacea, as reported previously. Additionally, we conducted an investigation into the biometric traits of virgin and generative Linaria cretacea individuals across different populations, including an analysis of their seed parameters. The morphometric parameters exhibited notable variations among the populations under investigation, with the exception of the seed measurements, which showed minimal to negligible variability. The species' coenopopulations are currently in a stable state, but the absence of adequate protection measures is a cause for concern. Therefore, it is crucial to undertake regular monitoring of their habitats and enhance environmental measures to safeguard their well-being. [ABSTRACT FROM AUTHOR]

Background: This study conducted a survey for establishing in-situ and ex-situ conservation measures for northern lineage plants that are vulnerable to climate change and for designating Forest Genetic Resource Reserve for 25 algific talus slope sites, which are specific areas of forest biodiversity. The survey was conducted in South Korea within a distance of 50 m to the east, west, north and south from the core area where wind blows to the algific talus slopes. The study was conducted once or twice per season from April 2016 to November 2021. New information:Vascular plants of 25 algific talus slope sites in South Korea included a total of 1,052 taxa of 125 families, 486 genera, 947 species, 23 subspecies, 75 variety and 7 forma. The maximum surveyed area was 0.09 km, accounting for only 0.00014% of the 62,860 km forest area in Korea, but comprise 22.27% of the 4,724 species of vascular plants in Korea. The algific talus slopes are areas rich in forest biodiversity. Six taxa were categorized as endangered, including Paeonia obovata Maxim. Sixty-seven taxa, including Astilboides tabularis (Hemsl.) Engl.; 58 taxa endemic to the Korean Peninsula, including Weigela subsessilis (Nakai) L.H. Bailey; and 317 taxa of floristic target plants were categorized as rare plants in the Red list. Further, 181 taxa were identified as northern lineage plants and 32 taxa, including Sillaphyton podagraria (H. Boissieu) Pimenov, were limestone area plants. Regarding alien plants, 75 taxa, including Oenothera biennis L., were identified and the naturalization and urbanization rates were 7.13% and 12.12%, respectively. Plants specific to the phytogeography of the 25 algific talus slope sites in this study were Vaccinium vitis-idaea L., Rosa koreana Kom., Syringa villosa Vahl subsp. wolfii (C.K. Schneid.) Jin Y.Chen & D.Y. Hong, Lonicera chrysantha Turcz. ex Ledeb., Tephroseris flammea (Turcz. ex DC.) Holub, among others. [ABSTRACT FROM AUTHOR]

Background. Herminium monorchis (L.) R. Br. – rare species of the Orchid family, included in the Red Book of Penza region. Monitoring of the cenopopulation of the species on the Olshansky solonetz is necessary to assess the current state and forecast in order to preserve it. Materials and methods. H. monorchis develops on soils of varying degrees of salinity in the composition of meadows of different types on the Olshanskiy solonetz. In 2013, 2021, 2023 geobotanical descriptions were made, the ontogenetic structure was studied, and the ecological density of the cenopopulation, the Δ and ω indices were determined. Results. The area of the H. monorchis cenopopulation on the Olshanskiy solonetz has not decreased over 10 years of observations. The species is confined to associations of saline and steppe meadows formed by Centaurea jacea, Equisetum arvense, Inula salicina, Senecio schvetzovii, Ononis arvensi, Calamagrostis epigeios, Thalictrum simplex. At low salinity, H. monorchis plays the role of an assector in them. With an increase in the degree of salinity, its participation in the composition of plant communities increases – it becomes a co-dominant and dominant. The ecological density of the cenopopulation is very high, increasing with increasing salt content. Population is normal. Ontogenetic spectra in 2013 are righthanded, with a predominance of generative individuals, in 2023 they are bimodal with a maximum on generative ones on immature plants. Self-maintenance of the population occurs mainly due to vegetative reproduction, which ensures the rejuvenation of individuals to the immature age state, and to a lesser extent by seed (a low proportion of juvenile individuals). A high renewability index indicates the stability of the population due to efficient reproduction. Indices of age and efficiency are typical for maturing and mature populations. Among the generative individuals, plants of reduced and low vitality predominate due to the toxic effect of salts. The life form of a vegetative annual allows the species to increase its competitiveness in saline conditions compared to other meadow grasses. Conclusions. The condition of the H. monorchis cenopopulation at the Olshanskiy solonetz is relatively favorable. Further monitoring of the state of the cenopopulation should be continued in order to timely identify possible adverse changes.

Accurate estimates of current and future habitat suitability are needed for species that may require assistance in tracking a shifting climate. Standard species distribution models (SDMs) based on occurrence data are the most common approach for evaluating climatic suitability, but these may suffer from inaccuracies stemming from disequilibrium dynamics and/or an inability to identify suitable climate regions that have no analogues within the current range. An alternative approach is to test performance with experimental introductions, and model suitability from the empirical results. We used this method with the Haleakalā silversword (Argyroxiphium sandwicense subsp. macrocephalum), using a network of out-plant plots across the top of Haleakalā volcano, Hawaiʻi. Over a ~ 5-year period, survival varied strongly across this network and was effectively explained by a simple model including mean rainfall and air temperature. We then applied this model to estimate current climatic suitability for restoration or translocation activities, to define trends in suitability over the past three decades, and to project future suitability through 2051. This empirical approach indicated that much of the current range has low suitability for long-term successful restoration, but also identified areas of high climatic suitability in a region where plants do not currently occur. These patterns contrast strongly with projections obtained with a standard SDM, which predicted continued suitability throughout the current range. Under continued climatic shifts, these results caution against the common SDM presumption of equilibrium between species' distributions and their environment, even for long-established native species. [ABSTRACT FROM AUTHOR]

Aim: Native biodiversity is threatened by the spread of non‐native invasive species. Many studies demonstrate that invasions reduce local biodiversity but we lack an understanding of how impacts vary across environments at the macroscale. Using ~11,500 vegetation surveys from ecosystems across the United States, we quantified how the relationship between non‐native plant cover and native plant diversity varied across different compositions of invading plants (measured by non‐native plant richness and evenness) and environmental contexts (measured by productivity and human activity). Location: Continental United States. Time Period: Surveys from 1990s‐present. Major Taxa Studied: Terrestrial plant communities. Methods: We fit mixed effects models to understand how native plant richness, diversity and evenness varied with non‐native cover. We tested how this relationship varied when non‐native cover interacted with non‐native plant richness and evenness, and with productivity and human activity. Results: Across the United States, communities with greater cover of non‐native plants had lower native plant richness and diversity but higher evenness, suggesting rare native plants can be lost while dominant plants decline in abundance. The relationship between non‐native cover and native community diversity varied with non‐native plant richness and evenness but was not associated with productivity and human activity. Negative associations were strongest in areas with low non‐native richness and evenness, characterizing plant communities that were invaded by a dominant non‐native plant. Main Conclusions: Non‐native plant cover provides a first approximation of invasion impacts on native community diversity, but the magnitude of impact depended on non‐native plant richness and evenness. Relationships between non‐native cover and native diversity were consistent in strength across continental scale gradients of productivity and human activity. Therefore, at the macroscale, invasive plant impacts on native plant communities likely depend more on the characteristics of the invading plants, that is the presence of a dominant invader, than on the environmental context. [ABSTRACT FROM AUTHOR]

Meliosma oldhamii Miq. is a deciduous arbor and a member of Sabiaceae. It is one of the rare and protected plants with outstanding ornamental and economic value in Jiangsu, China. In addition to the resource values indicated above, there are numerous other elements that require additional research, including the chloroplast (cp) genomic information. In this work, the complete cp genome sequence of M. oldhamii was assembled and characterized for the first time. The complete cp genome of M. oldhamii was 159,950 base pair (bp) in length, including a large single-copy (LSC) region of 87,147 bp, a small single-copy (SSC) region of 18,015 bp, and the inverted repeats (IRs) region of 27,394 bp. It contains 131 genes, including 37 tRNA genes, eight rRNA genes, 85 protein-coding genes, and one pseudogene. The overall GC content of M. oldhamii cp genome was 37.95%. The placement of M. oldhamii in the phylogenetic tree constructed using the complete cp genome is largely congruent with previous studies. The clustering of Meliosma is non-monophyletic, aligns more closely with existing morphological taxonomic studies, thereby enhancing the scholarly and scientific nature of this research. [ABSTRACT FROM AUTHOR]

Mining activities create disturbed and polluted areas in which revegetation is complicated, especially in northern areas. For the first time, the state of the ecosystems in the impact zone of tailings formed during the processing of rare earth element deposits in the Subarctic have been studied. This work aimed to reveal aspects of accumulation and translocation of trace and biogenic elements in plants (Avenella flexuosa (L.) Drejer, Salix sp., and Betula pubescens Ehrh.) that are predominantly found in primary ecosystems on the tailings of loparite ores processing. The chemical composition of soil, initial and washed plant samples was analyzed using inductively coupled plasma mass spectrometry. Factor analysis revealed that anthropogenic and biogenic factors affected the plants' chemical composition. A deficiency of nutrients (Ca, Mg, Mn) in plants growing on tailings was found. The absorption of REE (Ce, La, Sm, Nd) by A. flexuosa roots correlated with the soil content of these elements and was maximal in the hydromorphic, which had a high content of organic matter. The content of these elements in leaves in the same site was minimal; the coefficient of REE bioaccumulation was two orders of magnitude less than in the other two sites. The high efficiency of dust capturing and the low translocation coefficient of trace elements allow us to advise A. flexuosa for remediation of REE-contained tailings and soils. [ABSTRACT FROM AUTHOR]

Korean bellflower (Campanula takesimana Nakai) is a rare and perennial herb with medicinal and ornamental values, is endemic to the Ulleung Island of Korea. In this study, we investigated the dormancy-release and germination characteristics of C. takesimana (Campanulaceae) seeds by subjecting them to varying temperatures (5, 10, 15, 20, and 25°C and diurnal/nocturnal temperatures of 15/6, 20/10, and 25/15°C), cold stratification periods (0, 4, 8, or 12 weeks at 5°C), and gibberellic acid (GA3) concentrations (0, 10, 100, or 1,000 mg·L-1 at 15/6°C and 25/15°C) to identify the ideal seed propagation conditions. The seeds were stimulated to germinate (at 25°C, 12-h photoperiod with fluorescent lamps at 40 ± 10 μmol∙m-2∙s-1) after cold stratification. To examine the germination characteristics, the seeds were tested for water imbibition and found to readily absorb water. The seeds exhibited underdeveloped embryos during dispersal, showed final germination of 37.00% ± 4.43 at 25°C and were not influenced by temperature. The seeds subjected to 0, 4, 8, or 12 weeks of cold stratification germinated at a success rate of 22.00% ± 4.76, 87.00% ± 6.80, 79.00% ± 2.52, and 77.00% ± 1.91, respectively. Additionally, the germination characteristics, which were based on final germination, mean germination time, and germination velocity (Timson index), were significantly greater in the seeds pretreated with 1,000 mg·L-1 GA3 at 25/15°C than in seeds pretreated with 0 mg·L-1 GA3. Overall, the seeds broke dormancy with GA3 and short-term cold stratification. Therefore, we concluded that C. takesimana seeds have non-deep, simple, morphophysiological dormancy, and pretreatment with cold stratification and GA3 is required for effective seed propagation. [ABSTRACT FROM AUTHOR]

The responses of rare plants to environmental stressors will determine their potential to adapt to a rapidly changing climate. We used a common garden approach to evaluate how six populations of the annual San Diego thornmint (Acanthomintha ilicifolia Lamiaceae; listed as endangered in the state of California and as threatened by the US Fish and Wildlife Service) from across the species range respond in terms of growth (biomass, height, and width) and reproduction (seed production, floral production, and next generation seed viability) to experimental differences in water availability. We found a significant irrigation-by-population interaction on the aboveground growth, wherein the differences in the magnitude and direction of treatment did not correlate directly with climate variables in natural populations. With respect to reproduction, the low-irrigation treatment produced more seeds per plant, more reproductive individuals, and a larger proportion of viable seed in most, but not all, populations. The seed production and the effect of irrigation on seed production correlated positively with rainfall at wild source populations. These results suggest that Acanthomintha ilicifolia responds to water limitation by creating more and higher-quality seed, and that plants locally adapted to a higher annual rainfall show a greater plasticity to differences in water availability than plants adapted to a lower annual rainfall, a finding that can inform the in situ demographic management and ex situ collection strategy for Acanthomintha ilicifolia and other rare California annuals. [ABSTRACT FROM AUTHOR]

Premise: Many plant communities across the world are undergoing changes due to climate change, human disturbance, and other threats. These community‐level changes are often tracked with the use of permanent vegetative plots, but this approach is not always feasible. As an alternative, we propose using photogrammetry, specifically photograph‐based digital surface models (DSMs) developed using structure‐from‐motion, to establish virtual permanent plots in plant communities where the use of permanent structures may not be possible. Methods: In 2021 and 2022, we took iPhone photographs to record species presence in 1‐m2 plots distributed across alpine communities in the northeastern United States. We then compared field estimates of percent coverage with coverage estimated using DSMs. Results: Digital surface models can provide effective, minimally invasive, and permanent records of plant species presence and percent coverage, while also allowing managers to mark survey locations virtually for long‐term monitoring. We found that percent coverage estimated from DSMs did not differ from field estimates for most species and substrates. Discussion: In order to continue surveying efforts in areas where permanent structures or other surveying methods are not feasible, photogrammetry and structure‐from‐motion methods can provide a low‐cost approach that allows agencies to accurately survey and record sensitive plant communities through time. [ABSTRACT FROM AUTHOR]

Rare plant species are suggested to be less resistant to herbivores than common species. Their lower apparency and the fact that they often live in isolated populations, resulting in fewer herbivore encounters, might have led to the evolution of reduced defences. Moreover, their frequent lower levels of genetic diversity compared with common species could negatively affect their resistance against enemies. However, the hypothesis that plant resistance depends on plant regional and local rarity, independently of habitat and competitive and growth strategy, lacks evidence. To test this hypothesis, we assessed the performance and preference of one belowground and three aboveground generalist invertebrate herbivores from different taxonomic groups as indicators of plant resistance. Herbivores were fed a total of 62 regionally and locally rare and common plant species from Switzerland. We accounted for differences in a plant's growth and competitive strategy and habitat resource availability. We found that regionally and locally rare and common plant species did not generally differ in their resistance to most generalist herbivores. However, one herbivore species even performed better and preferred locally and regionally common plant species over rarer ones, indicating that common species are not more resistant, but tend to be less resistant. We also found that all herbivore species consistently performed better on competitive and large plant species, although different herbivore species generally preferred and performed better on different plant species. The latter indicates that the use of generalist herbivores as indicators of plant‐resistance levels can be misleading. Synthesis: Our results show that rare plant species are not inherently less resistant than common ones to herbivores. Instead, our results suggest that the ability of plants to allocate resources away from defence towards enhancing their competitive ability might have allowed plants to tolerate herbivory, and to become locally and regionally common. [ABSTRACT FROM AUTHOR]

Whether ex situ populations constructed in the limited nursery resources of botanical gardens can preserve enough genetic diversity of endangered plants in the wild remains uncertain. Here, a case study was conducted with Camellia tunghinensis, which is one of the species with the lowest natural distribution area in the sect. Chrysantha (golden camellia) of the family Theaceae. We investigated the genetic diversity and population structure of 229 samples from wild and ex situ populations using genotyping by sequencing (GBS). Core germplasm was constructed from these samples. The results showed that wild C. tunghinensis exhibited high genetic diversity, with observed heterozygosity of 0.257–0.293 and expected heterozygosity of 0.247–0.262. Compared with wild populations, the genetic diversity of ex situ populations established by transplanting wild seedlings was close to or even higher. However, the genetic diversity of those established by seed or cuttings of a few superior trees was lower. The Admixture analysis revealed that the structure of the ex situ populations derived from seeds and cuttings was relatively simple compared with the ex situ populations derived from transplanted wild seedlings and wild populations. These results suggested that direct transplanting of wild seedlings was more conducive to preserving the genetic diversity of endangered plants in the wild. In addition, wild populations demonstrated a small differentiation (mean FST = 0.044) among themselves, possibly due to long‐term and frequent gene flow between the wild populations. In contrast, moderate differentiation (mean FST > 0.05) was detected among ex situ populations and between ex situ and wild populations. This may be the combined result of the absence of gene flow pathways and strong selection pressure in various ex situ environments. Finally, 77 core germplasms were extracted from 229, likely representing the genetic diversity of C. tunghinensis. This study provides future strategies for the ex situ conservation and management of the golden camellia species and other rare and endangered plants. [ABSTRACT FROM AUTHOR]

When working with rare plant species, applying morphometric techniques is one of the main ways to obtain a representative data set on plant individuals and the state of particular populations growing in different ecological conditions and experiencing different degrees of anthropogenic load. Zygophyllum pinnatum, an understudied species growing on the territory of the Republic of Bashkortostan, the Orenburg region, and the Republic of Kazakhstan, is referred as a rare species. The purpose of the work is to study morphometric parameters and reveal the vitality structure of the Z. pinnatum coenopopulations in two regions of the Russian Federation (the Republic of Bashkortostan and Orenburg region) and in the north-west of the Republic of Kazakhstan (the Aktobe Region). Applying standard morphometric techniques, we analyzed the state of 16 coenopopulations of the species. Judging by most morphometric parameters, the leadership belongs to the individuals from the "Troitsk Cretaceous Mountains" coenopopulation located in the Sol-Iletsky District of Orenburg oblast, where, apparently, the most optimal plant conditions are formed (the absence of human impact and low projective cover of the grass stand to have a favorable effect). The minimum values for most parameters are recorded in the coenopopulations located on the territory of the Republic of Kazakhstan, resulting from arid growing conditions. The variability of most characters is within the normal range of the species response (Cv--5.0-44.6%). The discriminant function analysis revealed the morphostructural similarity of individuals from most coenopopulations. Regarding vitality, eight coenopopulations are prosperous, and another eight are depressed. The condition of the species coenopopulations is stable; however, the species is not provided with proper protection measures. Therefore, further monitoring of its habitats and improvement of environmental measures are necessary. [ABSTRACT FROM AUTHOR]

Magnolia wufengensis is a newly discovered rare and endangered species endemic to China. The primary objective of this study is to find the most suitable species distribution models (SDMs) by comparing the different SDMs to predict their habitat distribution for protection and introduction in China under climate change. SDMs are important tools for studying species distribution patterns under climate change, and different SDMs have different simulation effects. Thus, to identify the potential habitat for M. wufengensis currently and in the 2050s (2041–2060) and 2070s (2061–2080) under different climate change scenarios (representative concentration pathways RCP2.6, RCP4.5, RCP6.0, and RCP8.5) in China, four SDMs, Maxent, GARP, Bioclim, and Domain, were first used to compare the predicted habitat and explore the dominant environmental factors. The four SDMs predicted that the potential habitats were mainly south of 40° N and east of 97° E in China, with a high distribution potential under current climate conditions. The area under the receiver operating characteristic (ROC) curve (AUC) (0.9479 ± 0.0080) was the highest, and the Kappa value (0.8113 ± 0.0228) of the consistency test and its performance in predicting the potential suitable habitat were the best in the Maxent model. The minimum temperature of the coldest month (−13.36–9.84 °C), mean temperature of the coldest quarter (−6.06–12.66 °C), annual mean temperature (≥4.49 °C), and elevation (0–2803.93 m), were the dominant factors. In the current climate scenario, areas of 46.60 × 104 km2 (4.85%), 122.82 × 104 km2 (12.79%), and 96.36 × 104 km2 (10.03%), which were mainly in central and southeastern China, were predicted to be potential suitable habitats of high, moderate, and low suitability, respectively. The predicted suitable habitats will significantly change by the 2050s (2040–2060) and 2070s (2060–2080), suggesting that M. wufengensis will increase in high-elevation areas and shift northeast with future climate change. The comparison of current and future suitable habitats revealed declines of approximately 4.53%–29.98% in highly suitable habitats and increases of approximately 6.45%–27.09% and 0.77%–21.86% in moderately and lowly suitable habitats, respectively. In summary, these results provide a theoretical basis for the response to climate change, protection, precise introduction, cultivation, and rational site selection of M. wufengensis in the future. [ABSTRACT FROM AUTHOR]

Daphne mezereum of the Thymelaeaceae family is a medicinal shrub occurring naturally in Europe and under legal protection in Poland. In the present study, a protocol developed for mass propagation of February daphne from nodal explants is presented. Micropropagation is one of the in vitro techniques that allow the preservation of rare and valuable plants by developing efficient methods for their propagation. In the proliferation stage, explants were cultured in the Woody Plant Medium (WPM) with different cytokinins, and in the rooting stage on the semi-solid WPM medium with perlite, indole-3-butyric acid (IBA) in various concentrations was used. The maximum proliferation rate (five shoots per explant) was observed on the medium containing 4.14 μM of meta-Topolin (mT). When the regenerated shoots were rooted in vitro in the presence of IBA in various concentrations, that of 19.68 μM induced the highest number of roots per shoot (6.63) and the maximal root length (2.15 cm). It is also worth remembering that plants are often colonized by different groups of microorganisms, which also affect the diversity of the ecosystem. The endophytic bacteria inhabiting the D. mezereum shoots are Mycobacterium. [ABSTRACT FROM AUTHOR]