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Why and how organismal lineages radiate is commonly studied through either assessing abiotic factors (biogeography, geomorphological processes, and climate) or biotic factors (traits and interactions). Despite increasing awareness that both abiotic and biotic processes may have important joint effects on diversification dynamics, few attempts have been made to quantify the relative importance and timing of these factors, and their potentially interlinked direct and indirect effects, on lineage diversification. We here combine assessments of historical biogeography, geomorphology, climatic niche, vegetative, and floral trait evolution to test whether these factors jointly, or in isolation, explain diversification dynamics of a Neotropical plant clade (Merianieae, Melastomataceae). After estimating ancestral areas and the changes in niche and trait disparity over time, we employ Phylogenetic Path Analyses as a synthesis tool to test eleven hypotheses on the individual direct and indirect effects of these factors on diversification rates. We find strongest support for interlinked effects of colonization of the uplifting Andes during the mid-Miocene and rapid abiotic climatic niche evolution in explaining a burst in diversification rate in Merianieae. Within Andean habitats, later increases in floral disparity allowed for the exploitation of wider pollination niches (i.e. shifts from bee to vertebrate pollinators), but did not affect diversification rates. Our approach of including both vegetative and floral trait evolution, rare in assessments of plant diversification in general, highlights that the evolution of woody habit and larger flowers preceded the colonization of the Andes, but was likely critical in enabling the rapid radiation in montane environments. Overall, and in concert with the idea that ecological opportunity is a key element of evolutionary radiations, our results suggest that a combination of rapid niche evolution and trait shifts was critical for the exploitation of newly available niche space in the Andes in the mid-Miocene. Further, our results emphasize the importance of incorporating both abiotic and biotic factors into the same analytical framework if we aim to quantify the relative and interlinked effects of these processes on diversification. [ABSTRACT FROM AUTHOR]

Hibiscus liliiflorus , endemic to the Indian Ocean island of Rodrigues, is one of the rarest plant species in the world; only 2 wild individuals remain. Previously, when 4 wild individuals remained, the Mauritian Wildlife Foundation (MWF) in Rodrigues propagated cuttings of them in their nursery, then planted seedlings produced in the nursery into 3 outplanted populations on the island. Our goals were to: 1) assess whether all 4 original wild genotypes are represented in the MWF nursery; 2) determine whether ex situ living collections at international botanical gardens maintain unique genotypes of H. liliiflorus ; 3) assess whether nursery individuals have crossed or self-fertilized to produce seed and quantify their relative contributions to outplanted populations; and 4) provide recommendations for future conservation actions. We used a 2b-RADseq approach to produce 2,711 genome-wide single nucleotide polymorphisms (SNPs) from 98 samples. Genotype identity analysis, principal component analysis, and model-based clustering in STRUCTURE found 4 genotypes extant in Rodrigues but no unique genotypes in ex situ botanic garden collections. Only 3 genotypes are represented in the MWF nursery; the one remaining genotype is represented by an extant wild individual. Parentage analysis showed that seeds produced in the MWF nursery resulted from both self-fertilization and crossing between genotypes, a result supported by internal relatedness and hybrid index calculations. Each outplanted population is dominated by a subset of parental genotypes, and we propose actions to balance the parental contributions to outplanted populations. Our study highlights how genetic assessments of ex situ conservation projects help conserve critically endangered species. [ABSTRACT FROM AUTHOR]

Many organisms change their phenotype in response to the environment, a phenomenon called phenotypic plasticity. Although plasticity can dramatically change the phenotype of an organism, we hardly understand how this can affect biotic interactions and the resulting phenotypic selection. Here, we use fast cycling Brassica rapa plants in an experiment in the greenhouse to study the link between plasticity and selection. We detected strong plasticity in morphology, nectar, and floral scent in response to different soil types and aphid herbivory. We found positive selection on nectar and morphological traits in hand‐ and bumblebee‐pollinated plants. Bumblebee‐mediated selection on a principal component representing plant height, flower number, and flowering time (mPC3) differed depending on soil type and herbivory. For plants growing in richer soil, selection was stronger in the absence of herbivores, whereas for plants growing in poorer soil selection was stronger with herbivory. We showed that bumblebees visited tall plants with many flowers overproportionally in plants in poor soil with herbivory (i.e., when tall plants were rare), thus causing stronger positive selection on this trait combination. We suggest that with strong plasticity under most stressful conditions, pollinator‐mediated selection may promote adaptation to local environmental factors given sufficient heritability of the traits under selection. [ABSTRACT FROM AUTHOR]

Aims Harsh environmental conditions in alpine ecosystems shape vegetation structure into patches, where many different plant species cluster and grow together. Yet, which factors are important for the structure and dynamics of such plant–patch networks remains poorly understood. We aim to assess which and how environmental and biotic factors predict the assembly of plant–patch networks along a mountain range. Methods We examined the distribution of plant species in more than 5500 vegetation patches in 37 Mediterranean alpine grasslands distributed along a 500 m altitudinal gradient (National Park of Sierra Guadarrama, Spain). We established a plant–patch network for each grassland community and analyzed how nestedness and modularity vary with environmental (altitude, insolation and soil conditions) and biotic factors (number of species per plot, mean patch area and total pasture area). Important Findings Plant–patch networks showed consistent, non-random patterns characterized by a nested, but not modular, structure, which suggests that positive associations among co-occurring specialists promote their growth within patches as subsets of a pool with more generalist species. Both nestedness and modularity of plant–patch networks varied among grasslands. Specifically, nestedness decreased with increasing species per plot and increased with mean patch area, while it was independent of environmental variables; modularity increased with increasing pasture area and species per plot. The negative relationship between species per plot and nested patterns may be linked to the restricted number of species that can coexist within the same patch at a given size. Moreover, the positive relationship between patch size and nestedness indicates that the growth of rare plant species within vegetation patches occupied by more abundant species is facilitated in bigger rather than smaller patches. Furthermore, these results indicate that the nested assembly of vegetation patches may be independent of abiotic conditions. These findings suggest that large and unfragmented vegetation patches are fundamental for the maintenance of plant diversity in alpine grasslands. Looking at species distribution at fine spatial scales may shed new light on the biotic processes underlying plant network assembly and provide novel ways for conserving biodiversity. [ABSTRACT FROM AUTHOR]

Background Perennity of giant rosette species in combination with a single 'big bang' reproduction followed by death of the genetic individual is relatively rare among plants. Such long-lived monocarpic plants are usually slow growing and can be found in deserts, bogs or in alpine regions of the tropics or sub-tropics. Due to their longevity, monocarpic perennials risk losing everything before reproduction, which make them particularly susceptible to disturbances. Because of the inherent difficulties in assessing whether long-lived populations are growing or declining, usually neither their demography nor the consequences of increasing grazing pressure are known. Methods We used integral projection modelling (IPM) to measure the growth rate and passage time to flowering of Rheum nobile , a monocarpic perennial, and one of the most striking alpine plants from the high Himalayas. Rosettes which were no longer found due to disturbances or grazing by yaks were either treated as missing or as dead in two series of analysis, thereby simulating demography with and without the impact of grazing cattle. Data were collected from plants at 4500 m a.s.l. in Shangri-la County, Yunnan Province, south-west China. In four consecutive years (2011–2014) and in two populations, 372 and 369 individuals were measured, respectively, and size-dependent growth, survival and fecundity parameters were estimated. In addition, germination percentage, seedling survival and establishment probability were assessed. Key results The probability of survival, flowering and fecundity were strongly size dependent. Time to reach flowering size was 33.5 years [95 % confidence interval (CI) 21.9–43.3, stochastic estimate from pooled transitions and populations]. The stochastic population growth rate (λ s) of Rheum nobile was 1.013 (95 % CI 1.010–1.017). When disturbance by grazing cattle (yaks) was accounted for in the model, λ s dropped to values <1 (0.940, 95 % CI 0.938–0.943). Conclusion We conclude that natural populations of this unique species are viable, but that conservation efforts should be made to minimize disturbances by grazing and to protect this slow-growing flagship plant from the high Himalayas. [ABSTRACT FROM AUTHOR]

Globally, a small number of plants have adapted to terrestrial outcroppings of serpentine geology, which are characterized by soils with low levels of essential mineral nutrients (N, P, K, Ca, Mo) and toxic levels of heavy metals (Ni, Cr, Co). Paradoxically, many of these plants are restricted to this harsh environment. Caulanthus ampexlicaulis var. barbarae (Brassicaceae) is a rare annual plant that is strictly endemic to a small set of isolated serpentine outcrops in the coastal mountains of central California. The goals of the work presented here were to 1) determine the patterns of genetic connectivity among all known populations of C. ampexlicaulis var. barbarae , and 2) estimate contemporary effective population sizes (N e), to inform ongoing genomic analyses of the evolutionary history of this taxon, and to provide a foundation upon which to model its future evolutionary potential and long-term viability in a changing environment. Eleven populations of this taxon were sampled, and population-genetic parameters were estimated using 11 nuclear microsatellite markers. Contemporary effective population sizes were estimated using multiple methods and found to be strikingly small (typically N e < 10). Further, our data showed that a substantial component of genetic connectivity of this taxon is not at equilibrium, and instead showed sporadic gene flow. Several lines of evidence indicate that gene flow between isolated populations is maintained through long-distance seed dispersal (e.g. >1 km), possibly via zoochory. [ABSTRACT FROM AUTHOR]

Aims West Ordos Desert (WOD) in Inner Mongolia of China is characterized by unique geographical and ecological features to avoid the direct invasion of Quaternary Continental Glaciation, so it hosts many endangered relic species such as Tetraena mongolica, Ammopiptanthus mongolicus and Potaninia mongolica from Tertiary. However, how these plants utilize available water sources remains unknown. The objective of this study was to investigate the water utilization strategies of selected rare and endangered plant species in WOD by comparing hydrogen isotope ratios between their xylem water and possible water sources following four rainfall events of varying-intensities. Methods We measured the hydrogen isotope ratios of xylem water from T. mongolica, A. mongolicus and P. mongolica and an accompanying species Sarcozygium xanthoxylum and potential water sources (including precipitation and soil water in different soil layers from 0 to 150 cm) over 9 days following each of four varying-intensity rainfall events during the summer of 2012. And then calculated the percentage utilization of potential water sources by each species after each rainfall events using the linear mixing model. We also made the measurements of soil moisture and root biomass in favor of interpretation of plant water use strategies. Important Findings Tetraena mongolica, A. mongolicus and S. xanthoxylum primarily relied on deep soil water, whereas P. mongolica depended predominantly on rainwater. These rare and endangered desert plants had differential utilizations of available water sources, so some competition for limited water existed among some species. Tetraena mongolica had a competitive relationship in absorption of soil moisture with the same family species S. xanthoxylum, suggesting that T. mongolica and S. xanthoxylum should be restored separately at different areas in the WOD. Overall, this study provides a better understanding of water use strategies of these four plants and scientific evidence for protecting rare and endangered plants, maintaining regional species diversity, and developing effective vegetation restoration plans in the WOD. [ABSTRACT FROM AUTHOR]

Aims Reintroduction has become an important tool for the management of endangered plant species. We tested the little-explored effects of small-scale environmental variation, genotypic composition (i.e. identity of genotypes) and genotypic diversity on the population survival of the regionally rare clonal plant Ranunculus reptans. For this species of periodically inundated lakeshores, genetic differentiation had been reported between populations and between short-flooded and long-flooded microsites within populations. Methods We established 306 experimental test populations at a previously unoccupied lakeshore, comprising either monocultures of 32 genotypes, mixtures of genotypes within populations or mixtures of genotypes between populations. In 2000, three years after planting out at the experimental site, a long-lasting flood caused the death of half of the experimental populations. In 2003, an extreme drought resulted in the lowest summer water levels ever measured. Important Findings Despite these climatic extremes, 27% of the established populations survived in December 2003. The success of experimental populations largely differed between microsites. Moreover, the success of genotype monocultures depended on genotype and source population. Genetic differentiation between microsites played a minor role for the success of reintroduction. After the flood, populations planted with genotypes from different source populations increased in abundance, whereas populations with genotypes from single source populations and genotype monocultures decreased. In 2014, several small patches of Ranunculus clones were still present, but plants were strongly intermingled, which precluded their assignment to the original treatments. We conclude that sources for reintroductions need to be selected carefully. Moreover, mixtures of plants from different populations appear to be the best choice for successful reintroduction, at least in unpredictably varying environments. [ABSTRACT FROM AUTHOR]

Background: Carrizo Plain National Monument (San Joaquin Desert, California, USA) is home to many threatened and endangered species including the blunt-nosed leopard lizard (Gambelia sila). Vegetation is dominated by annual grasses, and shrubs such as Mormon tea (Ephedra californica), which is of relevance to our target species, the federally listed blunt-nosed leopard lizard, and likely also provides key ecosystem services. We used relatively nonintrusive camera traps, or trail cameras, to capture interactions between animals and these shrubs using a paired shrub-open deployment. Cameras were placed within the shrub understory and in open microhabitats at ground level to estimate animal activity and determine species presence. Findings: Twenty cameras were deployed from April 1st, 2015 to July 5th, 2015 at paired shrub-open microsites at three locations. Over 425,000 pictures were taken during this time, of which 0.4% detected mammals, birds, insects, and reptiles including the blunt-nosed leopard lizard. Trigger rate was very high on the medium sensitivity camera setting in this desert ecosystem, and rates did not differ between microsites. Conclusions: Camera traps are an effective, less invasive survey method for collecting data on the presence or absence of desert animals in shrub and open microhabitats. A more extensive array of cameras within an arid region would thus be an effective tool to estimate the presence of desert animals and potentially detect habitat use patterns. [ABSTRACT FROM AUTHOR]

Selective foraging by granivores can have important consequences for the structure and composition of plant communities, and potentially severe consequences for rare plant species. To understand how granivore foraging behavior affects common and rare plant species, diet selection should be viewed relative to the availability of alternative seed options, and with consideration of the individual attributes of those seeds (e.g., morphology, nutrient content). We examined the foraging decisions of Owyhee harvester ants, Pogonomyrmex salinus (Olsen), in semiarid grassland dominated by two species of grass, Poa secunda and Bromus tectorum, and two species of mustard, Sisymbrium altissimum and Lepidium papilliferum. The latter is a rare plant endemic to southwestern Idaho, and its seeds are readily consumed by P. salinus. We examined the diets of P. salinus colonies in June and July over three years and compared these values to the weekly availability of seeds on the ground in a 3-12-m radius around individual ant colonies. Small-seeded species (P. secunda, S. altissimum, and L. papilliferum) were usually overrepresented in the diet of ants relative to their availability, whereas the large seeds of B. tectorum were largely avoided despite being abundant and nutritious. The reduced travel time associated with carrying small seeds may overshadow differences in nutritional content among seed types, except in times when small seeds are in short supply. Lepidium papilliferum appears particularly vulnerable to seed predation, likely in part because it grows in dense patches that are easily exploited by foragers. [ABSTRACT FROM AUTHOR]

The coexistence of hermaphrodites and males (androdioecy) is rare in both plants and animals and has hitherto remained unknown in insects. Mongue et al. report a new case of androdioecy in the invasive haplodiploid insect Icerya purchasi, in which hermaphrodites can only self‐fertilize, but occasionally mate with males. Revealingly, I. purchasi shares several features with other androdioecious species such as the consequences of evolution from separate sexes, low outcrossing rates, and its colonizing habit. [ABSTRACT FROM AUTHOR]

Small population size, genetic diversity, and spatial patterns of vegetative spread are important aspects to consider when managing populations of rare clonal plant species. We used 5 variable nuclear simple sequence repeat nDNA loci to determine the extent of genet rhizome spread, examine the possibility of very small population sizes, and project how Bombus spp. (bumblebee) foraging may impact selfing (through geitonogamy) for a threatened lupine (Lupinus oreganus Heller) that sprawls through nonadventitious rhizomes. Genotyping identified 1 genet (27 × 13 m) that dominated about 30% of a study site, whereas 15 genets spread a maximum average distance of about 5.5 m (range 1.6 –27.1 m) and appeared to be well integrated with intervening genets. We found unexpectedly high genotype diversity, no evidence of a recent genetic bottleneck, and 5 of 6 patches had mean fixation index values that were near Hardy–Weinberg Equilibrium expectations. If the median maximum Bombus foraging distance observed in lupine patches (1.2 m) occurred within genotyped populations, a typical foraging flight would have >80% chance of occurring between different genets. Our study demonstrates that inferences associated with clonality, small population size, and inbreeding depression should be directly evaluated for rare vegetatively spreading plants. [ABSTRACT FROM PUBLISHER]

Background and Aims: A recent phylogenetic study based on multiple datasets is used as the framework for a more detailed examination of one of the ten molecularly circumscribed groups identified, the Ophrys fuciflora aggregate. The group is highly morphologically variable, prone to phenotypic convergence, shows low levels of sequence divergence and contains an unusually large proportion of threatened taxa, including the rarest Ophrys species in the UK. The aims of this study were to (a) circumscribe minimum resolvable genetically distinct entities within the O. fuciflora aggregate, and (b) assess the likelihood of gene flow between genetically and geographically distinct entities at the species and population levels. [ABSTRACT FROM PUBLISHER]

Hieracium cyathis (Ley) W. R. Linton (Asteraceae), Chalice Hawkweed, is a rare species endemic to Britain. It is a distinct member of Hieracium Section Oreadea, characterized by a short acladium and out-curved tips to the phyllaries. Historic records and current field survey indicate it has occurred in two localities in SW England and seven in South Wales. It is still present in all sites except for one Welsh locality, is significantly threatened at Cheddar Gorge, and two Welsh sites have only three plants each. Comparative morphology, cultivation experiments and amplified fragment length polymorphism (AFLP) analysis do not support the reported differences between material from SW England and Wales. AFLP analysis showed that every plant in the field was genetically similar but different, and minor genetic variation was found in one progeny array. It is a triploid (2 n = 27) with apomictic seed production, and 26% potentially viable pollen. It qualifies as ‘Near Threatened’ under the 2001 IUCN threat criteria. General guidelines for conservation of microspecies of Hieracium are discussed. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 156, 669–680. [ABSTRACT FROM AUTHOR]

Femeniasia balearica is the only representative of its genus and is endemic to a small area on the northern coast of Minorca (Balearic Islands, Spain). The entire range of the species covers only 18 km of coastline. It is extremely rare and classified as endangered in the National Catalogue of Threatened Species and as a priority species in the EU Habitats Directive. We carried out a census of current population size and estimated genetic diversity based on AFLP markers to facilitate conservation of this unique species. In the 66 individuals analysed (∼10% of population), 225 bands were scored and the level of diversity was relatively high. Three divergent population groups corresponding to geographical areas (Western, Central and Eastern) were identified. In AMOVA and Bayesian analyses, most of the diversity was found within populations but there was strong differentiation between the three population groups. Genetic and geographical distances between the populations were strongly correlated. Our results show that the populations of F. balearica are not genetically depauperate, in spite of their small sizes. Unexpectedly, our results suggest that as many as three MUs (management units) should be recognized in this very small area, because the low levels of gene flow among them indicate contemporary demographic independence. © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society, 2007, 153, 97–107. [ABSTRACT FROM AUTHOR]

The article studies the conservation of endemic plants in the eastern north region of the United States. The conservation of rare plants, such as the endemic plants, is a significant goal. Plant endemics pose challenges and opportunities for conservation. The cedar glades, dolomite outcrops, balsa and granite outcrops are having endemic species and acting as island archipelagos that have dispersal between them. The local extinctions will not be restored by natural immigration on reasonable time scales.

• Background and Aims For rare endemics or endangered plant species that reproduce both sexually and vegetatively it is critical to understand the extent of clonality because assessment of clonal extent and distribution has important ecological and evolutionary consequences with conservation implications. A survey was undertaken to understand clonal effects on fine-scale genetic structure (FSGS) in two populations (one from a disturbed and the other from an undisturbed locality) of Echinosophora koreensis, an endangered small shrub belonging to a monotypic genus in central Korea that reproduces both sexually and vegetatively via rhizomes.• Methods Using inter-simple sequence repeats (ISSRs) as genetic markers, the spatial distribution of individuals was evaluated using Ripley''s L(d)-statistics and quantified the spatial scale of clonal spread and spatial distribution of ISSR genotypes using spatial autocorrelation analysis techniques (join-count statistics and kinship coefficient, Fij) for total samples and samples excluding clones.• Key Results A high degree of differentiation between populations was observed (ΦST(g) = 0·184, P < 0·001). Ripley''s L(d)-statistics revealed a near random distribution of individuals in a disturbed population, whereas significant aggregation of individuals was found in an undisturbed site. The join-count statistics revealed that most clones significantly aggregate at ≤6-m interplant distance. The Sp statistic reflecting patterns of correlograms revealed a strong pattern of FSGS for all four data sets (Sp = 0·072–0·154), but these patterns were not significantly different from each other. At small interplant distances (≤2 m), however, jackknifed 95 % CIs revealed that the total samples exhibited significantly higher Fij values than the same samples excluding clones.• Conclusion The strong FSGS from genets is consistent with two biological and ecological traits of E. koreensis: bee-pollination and limited seed dispersal. Furthermore, potential clone mates over repeated generations would contribute to the observed high Fij values among genets at short distance. To ensure long-term ex situ genetic variability of the endangered E. koreensis, individuals located at distances of 10−12 m should be collected across entire populations of E. koreensis. [ABSTRACT FROM AUTHOR]

• Background There is a compelling need to protect natural plant communities and restore them in degraded landscapes. Activities must be guided by sound scientific principles, practical conservation tools, and clear priorities. With perhaps one-third of the world''s flora facing extinction, scientists and conservation managers will need to work rapidly and collaboratively, recognizing each other''s strengths and limitations. As a guide to assist managers in maintaining plant diversity, six pragmatic models are introduced that are already available. Although theoretical models continue to receive far more space and headlines in scientific journals, more managers need to understand that pragmatic, rather than theoretical, models have the most promise for yielding results that can be applied immediately to plant communities.• Six Pragmatic Models For each model, key citations and an array of examples are provided, with particular emphasis on wetlands, since ‘wet and wild’ was my assigned theme for the Botanical Society of America in 2003. My own work may seem rather prominent, but the application and refinement of these models has been a theme for me and my many students over decades. The following models are reviewed: (1) species–area: larger areas usually contain more species; (2) species–biomass: plant diversity is maximized at intermediate levels of biomass; (3) centrifugal organization: multiple intersecting environmental gradients maintain regional landscape biodiversity; (4) species–frequency: a few species are frequent while most are infrequent; (5) competitive hierarchies: in the absence of constraints, large canopy-forming species dominate patches of landscape, reducing biological diversity; and (6) intermediate disturbance: perturbations such as water level fluctuations, fire and grazing are essential for maintaining plant diversity.• Conclusions The good news is that managers faced with protecting or restoring landscapes already have this arsenal of tools at their disposal. The bad news is that far too few of these models are appreciated. [ABSTRACT FROM AUTHOR]

New specimens ofCooksoniaandHostinellaare described from the Bertie Group of Ontario and New York State, which is dated by faunas as latest Silurian (Přídolí). The rare plant fossils are unusual in that they are preserved in fine-grained, slightly argillaceous dolostones (‘waterlime’) rather than clastic rocks. At least two species ofCooksoniaare present, one with± globular sporangial morphology close toC. hemisphaericaLang. Those with ellipsoidal/discoidal sporangia are compared withC. pertoniLang,C. paranensisGerrienneet al. andC. bohemicaSchweitzer, the latter represented by a single specimen from the Přídolí of the Czech Republic. However, the paucity of specimens, which prevents assessment of taphonomic influences on shape, combined with the absence of any anatomical features and the gross morphological simplicity of the fossils, precludes specific assignment. Specimens ofHostinellainclude one in which apices and a lateral basal structure resembling a root are preserved. It is concluded that the Laurentian assemblage of Ontario and New York State is less diverse and disparate than coeval assemblages, which are also preserved in marine rocks. Its preservation in limestones may have been facilitated by the hypersalinity inferred from various sedimentary features, which would restrict the activity of many decomposers. © 2004 The Linnean Society of London,Botanical Journal of the Linnean Society, 2004,146, 399–413. [ABSTRACT FROM AUTHOR]

Discusses the preservation of rare plants in urban centers of the U.S. Importance of habitat protection to ecologists and conservation biologists; Preservation of biological diversity; Ownership of rare plant habitat; Spending of the U.S. Fish & Wildlife Service on behalf of endangered species; Solution of the involvement of more volunteers in management and monitoring activities.

Discusses conservation efforts to establish a living collection of rare and endangered plants in botanical gardens. Number of plant species known to be endangered in the world and in the United States according to the World Conservation Monitoring Centre of the International Union for Conservation of Nature and Natural Resources; Impact of global climate change on the policy of collecting rare and endangered plants; Discussion of the best methods to preserving population and species diversity.

Discusses various methods of conserving rare and endangered plants. Tissue culture; Seed storage; Ways to preserve species.

The article reports that Hawaii's National Tropical Botanical Garden (NTBG) have used drones to discover new populations of several plants listed as critically endangered on the International Union for Conservation of Nature (IUCN) Red List. The rarest plant spotted was laukahi that has been used in traditional Hawaiian healing to disinfect wounds, as well as to treat boils and high blood pressure

More than 10% of all plant species in the US are threatened with extinction. Recently, a group of botanists and plant conservators, drawn from leading arboretums and botanical gardens, formed the Center for Plant Conservation to collect and preserve these endangered plants. The collection will represent a living genetic library.

Background and Aims Small populations of rare plant species are increasingly reported to have high levels of reproductive failure. The objective of this study was to understand the principal constraints on sexual reproduction in small fragmented populations of a rare clonal self-incompatible plant. Methods The pollinator spectrum, diversity of flower colour, natural pollination and fruit-set levels of L. borealis were examined in Scotland. Artificially crossed seed production was compared within and between different flower colour types and patches. Key Results Linnaea borealis was pollinated by a diverse spectrum of insect species and the principal pollinators were muscid, syrphid and empid flies which mostly moved only small distances (L. borealis to be highly self-incompatible and artificial crosses within and between patches and flower colour types confirmed that low fruit success was the result of a lack of compatible mates and limited pollen movement between them. Evidence of isolation from pollen exchange was apparent at as little as 6 m and severe at 30 m and beyond. Conclusions Limited mate availability and isolation from pollen exchange compromise the reproductive success of fragmented populations of L. borealis in Scotland. A diversity of compatible mates situated within close proximity ( [ABSTRACT FROM AUTHOR]

The article presents a profile of botanist John Bartram. In 1729, Bartram built a garden with five acres of land where he planted different floral varieties he found near his farm in Darby, Pennsylvania. Eventually it contained a vast variety of rare native species, rivaling all other American colonial gardens. That great variety brought Bartram to the attention of European scientists. Bartram built a greenhouse as an addition to his botanical garden in 1760. Bartram earned his greatest honor when he was appointed by King George III of Great Britain as the Royal Botanist in the American colonies.