Premise Diversification of Camassia (Asparagaceae) in North America has shaped variety in morphological, ecological, and reproductive traits, and resulted in a classification with ambiguity in taxon boundaries, including numerous putative subspecies. Phylogenetic analyses of restriction-site-associated DNA sequences (RADseq) allowed new insights into its evolution and taxonomy, enhancing understanding of basal relationships, geographic patterns, taxonomic boundaries, and potential new species. Methods A total of 157 individuals in 71 populations across all 15 putative taxa of Camassia and 42 outgroup individuals in 21 populations from Hastingsia and Chlorogalum were sampled and genomic libraries were generated using the modified single-digest RADseq method known as multiplexed shotgun genotyping. Assembly in ipyrad included targeted comparisons across a range of parameters that influence homology assessment and amount of missing data, with analysis of the set of resulting datasets in RAxML and SVDquartets followed by comparison and summary across the sets of trees. Results and Conclusions Increasing the number of sampled loci improved phylogenetic signal despite concurrent increases in missing data. Each taxon was generally cohesive on the phylogenies, but some species and subspecies were not monophyletic. Results suggest that there was an early separation of C. howellii and C. leichtlinii from the rest of the genus during diversification. Different analysis parameters supported either a clade of both species as sister to the remainder of the genus, or C. howellii alone as sister. Relationships among all relatively deep clades within the genus were well supported. Within species, C. leichtlinii had particularly robust support for relationships compared to others in Camassia, and geographic patterns corresponding to the diversification of some subclades were resolved. The eight subspecies of C. quamash largely formed two main clades. Although most subspecies showed sufficient phylogenetic, morphological, or ecological distinctiveness to maintain recognition, we recommend synonymizing C. quamash ssp. intermedia into C. quamash ssp. maxima. Some outlier individuals of C. quamash were resolved with other species. For example, the status of C. quamash ssp. utahensis was called into question by a well-supported division placing two populations with C. cusickii. In the disjunct species complex distributed further east in North America (C. scilloides+), results confirmed at least one progenitor-derivative species pair (C. angusta arising from C. scilloides) and some evidence for a potential new taxon closely related to C. angusta. Overall, these taxa have diversified in traits that can result in genetic isolation, such as differences in flowering seasons and ecological preferences, but there also are indications of some continued gene flow among both subspecies and species.

PREMISE:Understanding genetic and morphological variability helps efforts to sustain landscapes and develop effective species concepts for resolving difficult groups. To unravel puzzling relationships and range disjunctions, we applied morphometrics, phenology, phylogenetics and population genetics in Camassia species with cultural, ecological, and conservation value, asking: Do the unusual Camassia populations in northeastern California represent previously unrecognized, disjunct C. howellii? Do C. howellii, C. leichtlinii, and C. quamash maintain diagnostic features in allopatry or sympatry? Are C. quamash subsp. breviflora and subsp. linearis taxonomically distinct? METHODS:We evaluated 34 Camassia populations in situ for morphometric traits, phenology, and habitat type, collecting tissue for population microsatellite and phylogenetic analyses (rpl16, trnD-trnT). Fieldwork and genetic analyses of Camassia species allowed hypothesis testing of all criteria. RESULTS:Oregon and California populations of C. howellii shared 94-95% morphospace but differed significantly from C. leichtlinii and C. quamash, primarily in having more basal leaves, subglobose fruits, and smaller flowers that open in mid-late afternoon, closing at sunset without reopening. Both microsatellite and phylogenetic data indicated separation of the three species, with slight genetic differentiation between the disjunct populations of C. howellii. Subspecies of C. quamash differed morphologically and genetically, with clear phylogenetic separation. CONCLUSIONS:Integrative approaches proved effective, affirming disputed species identities and upholding subspecific status for C. quamash subsp. linearis. For C. howellii, population genetic differentiation between disjunct regions appears congruent with phylogenetic analyses. Slight morphological differentiation of Oregon and California populations is consistent with geographic isolation, implying subspecific genetic divergence worthy of future study.

Invasive plants negatively impact natural areas and impose huge costs associated with control and management. A new approach to significantly reduce these effects is to identify species in the earliest stages of spread, using data collected by public gardens across North America. Known as Public Gardens as Sentinels against Invasive Plants (PGSIP), this network includes multiple gardens, each contributing reports of these problematic species to a shared database using standardized guidelines. We examined this dataset to identify newly spreading species being noticed within gardens within different regions and determined whether they have been reported as state-listed/regulated/noxious outside gardens. As of November 2024, 53 PGSIP gardens in 28 U.S. states and Canadian provinces had submitted 996 reports, consisting of 597 unique species. The most commonly listed species were Amur corktree (Phellodendron amurense Rupr.), burning bush [Euonymus alatus (Thunb.) Siebold], and wintercreeper [Euonymus fortunei (Turcz.) Hand.-Maz.]. Other less frequently listed species included golden rain tree (Koelreuteria paniculata Laxm.), Norway maple (Acer platanoides L.), and castor aralia [Kalopanax septemlobus (Thunb.) Koidz.]. Of the 597 species, 36% were not listed by any state or province; gardens also had several species on watchlists, including Japanese tree lilac [Syringa reticulata (Blume) H. Hara] and Siberian squill (Scilla siberica Andrews). Our results demonstrate the utility of the approach and value of the database. This information can now inform the efforts of land managers, invasion biologists, the horticultural industry, and agencies tasked with invasive plant monitoring and assessment.

As tornados become increasingly common with global climate change, recovery of the woody vegetation in temperate forests is imperative to maintain an intact ecosystem. In many urbanized landscapes, invasive species are also increasing and could interfere with natural recovery from environmental disturbance. We quantified the impact and 17-year recovery from a major tornado in a temperate deciduous forest. We used vegetational surveys in southwestern Ohio at the Harris M. Benedict Nature Preserve, where approximately a third of this site was damaged by a tornado in 1999. Plots were established in the tornado-damaged area and the nearby undisturbed forest to examine forest recovery of trees/saplings, shrubs and vines, and tree seedlings during 2003, 2006, 2010, and 2016/2017. The number of tree saplings, shrubs, and vines increased immediately after the tornado, but then declined by 2010, relative to the undisturbed forest. Forest tree recruitment was lower in tornado-damaged sites with fewer tree seedlings, but more saplings. Tree diversity was also affected by Agrilus planipennis (Emerald Ash borer) which targeted native ash trees within this time period. Despite an initial increase in shrubs and vines in the damaged area, the diversity and density of shrubs approached equality in both sites by 2016. Most shrubs in both sites were the invasive Lonicera maackii (Amur honeysuckle). In tornado sites, honeysuckle thinned out over time, leaving larger shrubs with greater mean basal diameter compared to the undisturbed forest. Other woody invasive species were also more prevalent in the damaged area, but increased in number in both locations by 2017. The forest has the capability to begin to recover from the initial tornado, but its future composition may differ from its initial trajectory due to invasive species, loss of ash trees, and anthropogenic impacts within the urban landscape.

Many insular plant taxa naturally consist of small populations, which are increasingly impacted today by herbivory, climate change, and competition with invasive plants. Are some insular species fated to extinction or do they still have potential to recover? To help explore this question, we studied Schiedea adamantis, a federally endangered shrub from the Hawaiian island of O'ahu where it was originally known as a single population. This population underwent a population crash in the late 1990s, declining from >250 plants to a handful of plants before several more individuals were discovered nearby. Fortunately, plants grown from seed obtained before the bottleneck had been maintained ex situ in California. Using microsatellite markers, we confirmed that levels of genetic variation were lower in the bottlenecked population compared to the pre- bottleneck and offspring collections, but overall levels remained moderate in the wild population despite the severe reduction in size. The four remaining field individuals consisted of one plant that likely persisted through the bottleneck and its progeny. The ex situ offspring collection contained four unique alleles, indicating the value of these collections maintained offsite. Subsequently, new plants located downslope from the original population and a second genetically different population on the same island were also discovered, although numbers continue to decline. In addition to ongoing reintroduction efforts, levels of genetic variation and discovery of new individuals holds promise for in situ survival of this species, but only if its habitat can be protected from fire, increased drought, and competition from invasive species.

Premise of research. As the second leading cause of biodiversity loss worldwide, invasive species have been introduced accidentally or intentionally into many locations. To prevent their continued spread, identifying common pathways of introduction is critical, as Sarah Reichard emphasized in her classic 1994 study in which she analyzed 235 woody species considered invasive in the United States at that time and reported that the majority had current or historical uses in horticulture.Methods. We now update her classic study with a literature review and expand it to herbaceous species by examining the origin of species identified as invasive today but within the Midwestern United States.Pivotal results. Of the 295 invasive species in this region, most introductions were through the ornamental trade, comprising 87.1% of trees and shrubs, 81.0% of vines, and 29.7% of terrestrial and aquatic herbs. We found that 85.5% of 83 invasive tree, shrub, and vine taxa in the Midwestern United States were associated with horticulture, compared with Reichard's national estimate of 82% of 235 species nationwide.Conclusions. In the 29 years since Reichard's review, the ornamental pathway continues today to be an avenue for the introduction of some plant species that later become invasive in the Midwestern United States, and, as such, the horticulture field could be effective in helping to reduce future plant invasions.

Functions to simulate monarch migration under set weather conditions. Data for repsirometry measurements and weather stations are also included in ZIP folders. Functions include working example of movement based on literature values for thresholds. Functions can be modified for other species as needed. Weather station data were collected from NOAA LCD stations. Alternative data sources include Wunderground Personal Weather Station datasets. However, Wunderground requires an API to access their data unless you have a PWS in their system. Connecting a PWS to wunderground provides you an API key for accessing data.

Migration is an energetically taxing phenomenon as animals move across vast, heterogeneous landscapes where the cost of transport is impacted by permissible ambient conditions. In this study, we assessed the energetic demands of long-distance migration in a multigenerational ectothermic migrant, the monarch butterfly (Danaus plexippus). We tested the hypotheses that temperature-dependent physiological processes reduce energy reserves faster during migration than previously estimated, and that increasing climatic temperatures resulting from the climate crisis will intensify baseline daily energy expenditure. First, we reared monarchs under laboratory conditions to assess energy and mass conversion from fifth instar to adult stages, as a baseline for migratory adult mass and ontogenetic shifts in metabolic rate from larvae to adult. Then, using historical tag-recapture data, we estimated the movement propensity and migratory pace of autumn migrants using computer simulations and subsequently calculated energy expenditure. Finally, we estimated the energy use of monarchs based on these tag-recapture data and used this information to estimate daily energy expenditure over a 57 year period. We found support for our two hypotheses, noting that incorporating standard metabolic rate into estimates of migratory energy expenditure shows higher energy demand and that daily energy expenditure has been gradually increasing over time since 1961. Our study shows the deleterious energetic consequences under current climate change trajectories and highlights the importance of incorporating energetic estimates for understanding migration by small, ectothermic migrants.

An important route of introduction of some nonnative species that subsequently become invasive in the United States is through horticulture. One such plant is Euonymus fortunei (Turcz.) Hand.-Maz., commonly known as wintercreeper, an evergreen groundcover with more than 52 different horticultural varieties, which is still sold at many plant nurseries and garden centers in the midwestern United States. Although several states have recognized E. fortunei as an invasive species, it is unknown how its escape from cultivation has occurred and even the identity of spreading populations, including whether hybrids or cultivars are involved. Using codominant microsatellite markers, we sampled multiple invasive populations in Ohio, Kentucky, Kansas, and Minnesota and compared their genotypes with commercially available cultivars to determine how spread has occurred. All samples collected from invasive populations were genetically identical to one another and matched perfectly with the ‘Coloratus’ cultivar, the only cultivar to exhibit polyploidy. The data also suggest that E. fortunei may potentially reproduce via apomixis and/or clonally through propagule fragments, which can quickly fix favorable genotypes within a population. To curb continued invasive spread, we suggest that Coloratus be removed from commercial sale and distribution. We also propose that land managers, horticultural and landscaping businesses, and governmental agencies carefully monitor other Euonymus cultivars for invasive potential and spread.

PREMISE:Evolution of separate sexes from hermaphroditism often proceeds through gynodioecy, but genetic constraints on this process are poorly understood. Genetic (co-)variances and between-sex genetic correlations were used to predict evolutionary responses of multiple reproductive traits in a sexually dimorphic gynodioecious species, and predictions were compared with observed responses to artificial selection. METHODS:Schiedea (Caryophyllaceae) is an endemic Hawaiian lineage with hermaphroditic, gynodioecious, subdioecious, and dioecious species. We measured genetic parameters of Schiedea salicaria and used them to predict evolutionary responses of 18 traits in hermaphrodites and females in response to artificial selection for increased male (stamen) biomass in hermaphrodites or increased female (carpel, capsule) biomass in females. Observed responses over two generations were compared with predictions in replicate lines of treatments and controls. RESULTS:In only two generations, both stamen biomass in hermaphrodites and female biomass in females responded markedly to direct selection, supporting a key assumption of models for evolution of dioecy. Other biomass traits, pollen and ovule numbers, and inflorescence characters important in wind pollination evolved indirectly in response to selection on sex allocation. Responses generally followed predictions from multivariate selection models, with some responses unexpectedly large due to increased genetic correlations as selection proceeded. CONCLUSIONS:Results illustrate the power of artificial selection and utility of multivariate selection models incorporating sex differences. They further indicate that pollen and ovule numbers and inflorescence architecture could evolve in response to selection on biomass allocation to male versus female function, producing complex changes in plant phenotype as separate sexes evolve.

Abstract Premise Of the approximately 430 species of oaks (Quercus spp.) that have been assessed, 31% are threatened with extinction and in need of safeguarding. However, oak seeds cannot be seed banked, and thus rely on alternative strategies such as in vitro culture for ex situ conservation. One challenge to this approach is low culture initiation rates. Our objective was to identify factors that may improve the establishment of shoot cultures in vitro using new growth collected from mature trees. Methods Shoot cuttings were harvested from individuals of five different oak species (Q. alba, Q. bicolor, Q. macrocarpa, Q. muehlenbergii, and Q. palustris). Shoots were cultured onto medium with or without 50 µM silver thiosulfate (STS), a known inhibitor of the stress hormone ethylene. Cultures were grown for one month, at which point shoots were assessed for survival. Results Shoot survival was significantly greater in shoots cultured on medium containing STS compared to the control group, with the overall survival rate increasing from 65% to 73%. Discussion Increasing the survival rate of newly established cultures is important in ensuring that material collected from endangered species has the best chance for survival, which is critical for successful ex situ conservation.

In spite of the remarkable progress made in the development of safe and effective vaccines against COVID-19, deployment of respiratory protective devices remains vital for mitigating the transmission of SARS-CoV-2 during the ongoing pandemic. In this study, we evaluated double masking, which entails layering a fitted over-mask on top of a surgical mask. A previously validated manikin-based protocol was used to evaluate the performance of a surgical mask with an over-mask made of silk or cotton. We showed that double masking can significantly enhance the mask???s source control capabilities by reducing an aerosol emission from a coughing or sneezing wearer while maintaining a reasonable breathability and comfort level. The data obtained in this study, as well as the results recently reported by other investigators, suggest that an over-mask made of silk fabric has several advantages over one made of cotton. Moreover, silk over-masks have the added benefit of providing a reusable protective outer layer for surgical masks as silk is hydrophobic and increases aerosol particle collection. Not only can double masking reduce viral or bacterial transmission, but it can also promote surgical mask longevity, thereby reducing global waste and pollution associated with the use of disposable surgical masks. Finally, an additional study with five human subjects revealed no significant differences in perceived comfort (measured by proxies such as relative humidity, temperature, and CO2 level inside the mask) between single masking and double masking, as well as between double masking with either a silk or cotton over-mask.

Public gardens can help prevent detrimental effects of plant invasions by collecting and sharing data on taxa spreading from cultivation early in the invasion process, thereby acting as sentinels of plant invasion. Existing initiatives have called for public gardens to adopt measures preventing plant invasion, but it is unclear what actions individual gardens are implementing, as there is no formal mechanism for communicating their progress. This study used internal lists of escaping taxa from seven public gardens in the Midwestern United States and Canada to demonstrate how public gardens can collectively contribute data that is critical to assessing potential invasiveness. It also reveals methodological differences in how gardens develop their lists of escaping plants, leading to recommendations for standardization. Data pooled across gardens yielded 769 species spreading from cultivation at one or more gardens. Eight woody species were listed by all gardens despite not consistently being recognized as invasive by states and provinces containing the gardens; some species recorded by multiple gardens did not appear on any invasive lists. While it may be premature to call taxa escaping from cultivation at a few public gardens “invasive” or even “potentially invasive”, these plants should be monitored and evaluated with this information shared to facilitate stronger conclusions about risk. Thus, public gardens have a unique expertise in assisting invasive plant efforts as sentinels, particularly if challenges related to methodological inconsistencies and data sharing are suitably addressed, which is herein recommended through the adoption of a set of standardized guidelines.

Do all plant biologists worldwide have equal access to novel methods, enabling them to be equally productive, publish, and receive credit for their research? Or does reduced access to cutting‐edge techniques in countries with lower financial resources create an inequity for researchers located there? Such disparities and biases do exist within our discipline and must be addressed if we are to move forward as a more just society. Applications in Plant Sciences has taken steps to address this important issue of research inequity, as outlined below. We now call upon the entire botanical community—researchers, editors and reviewers, funding agencies, and publishers—to work together toward a more equitable environment for all researchers around the world.

Plants growing along roadways are often exposed to vehicle exhaust containing both particulate matter (PM) and various gases that could affect gas exchange and thus plant reproduction. To investigate effects of diesel exhaust exposure on plant ecophysiology, growth, and fecundity, individuals of soybean ( Glycine max (L.) Merr.) and chicory ( Cichorium intybus L.) were exposed to either exhaust from a diesel generator or ambient air. Exposure occurred daily over a 5-day period (beginning 18 June 2013) using open-top chambers in an agricultural field in southwestern Ohio, United States. Plants were evaluated at 3 times (before, directly after exposure, and following a 5.5-week post-treatment recovery period) for photosynthetic rate ( A ), stomatal conductance ( g ), water use efficiency ( WUE ), stomatal clogging due to PM deposition, and number of nodes. Aboveground biomass, fruit number, mean seed number, and seed mass were measured for soybean after the recovery period. In soybean, A minimally decreased with exposure to diesel exhaust (compared to the control), but an increase in g and a decrease in WUE were detected after the exhaust treatment. Chicory exhibited a relatively low increase in A after the treatment, but there were no clear differences in g or WUE . Growth and fecundity were similar among all soybean plants directly after treatment, but after 5.5 weeks plants exposed to diesel exhaust had increased vegetative biomass while exhibiting no difference in fecundity. These plant species reacted differently to short-term diesel exhaust exposure, suggesting that the impact of diesel exhaust will depend on both the plant species and its physiology.

Background The worldwide shortage of single-use N95 respirators and surgical masks due to the COVID-19 pandemic has forced many health care personnel to prolong the use of their existing equipment as much as possible. In many cases, workers cover respirators with available masks in an attempt to extend their effectiveness against the virus. Due to low mask supplies, many people instead are using face coverings improvised from common fabrics. Our goal was to determine what fabrics would be most effective in both practices. Methods and findings We examined the hydrophobicity of fabrics (silk, cotton, polyester), as measured by their resistance to the penetration of small and aerosolized water droplets, an important transmission avenue for the virus causing COVID-19. We also examined the breathability of these fabrics and their ability to maintain hydrophobicity despite undergoing repeated cleaning. Tests were done when fabrics were fashioned as an overlaying barrier and also when constructed as do-it-yourself face coverings. As a protective barrier and face covering, silk is more effective at impeding the penetration and absorption of droplets due to its greater hydrophobicity relative to other tested fabrics. Silk face coverings repelled droplets as well as masks, but unlike masks they are hydrophobic and can be readily sterilized for immediate reuse. Conclusions Silk is an effective hydrophobic barrier to droplets, more breathable than other fabrics that trap humidity, and are readily re-useable via cleaning. Therefore, silk can serve as an effective material for protecting respirators under clinical conditions and as a material for face coverings.

The worldwide shortage of single-use N95 respirators and surgical masks due to the COVID-19 pandemic has forced many health care personnel to use their existing equipment for as long as possible. In many cases, workers cover respirators with available masks in an attempt to extend their effectiveness against the virus. Due to low mask supplies, many people instead are using face coverings improvised from common fabrics. Our goal was to determine what fabrics would be most effective in both practices. Under laboratory conditions, we examined the hydrophobicity of fabrics (cotton, polyester, silk), as measured by their resistance to the penetration of small and aerosolized water droplets, an important transmission avenue for the virus causing COVID-19. We also examined the breathability of these fabrics and their ability to maintain hydrophobicity despite undergoing repeated cleaning. Laboratory-based tests were conducted when fabrics were fashioned as an overlaying barrier for respirators and when constructed as face coverings. When used as material in these two situations, silk was more effective at impeding the penetration and absorption of droplets due to its greater hydrophobicity relative to other tested fabrics. We found that silk face coverings repelled droplets in spray tests as well as disposable single-use surgical masks, and silk face coverings have the added advantage over masks such that they can be sterilized for immediate reuse. We show that silk is a hydrophobic barrier to droplets, can be more breathable than other fabrics that trap humidity, and are re-useable via cleaning. We suggest that silk can serve as an effective material for making hydrophobic barriers that protect respirators, and silk can now be tested under clinical conditions to verify its efficacy for this function. Although respirators are still the most appropriate form of protection, silk face coverings possess properties that make them capable of repelling droplets.

Introduced from Europe to North America in the early 19th century as an ornamental shrub and for medicinal purposes, common buckthorn ( Rhamnus cathartica L.) has since spread and naturalized throughout regions of the United States and Canada. The purpose of this study was to investigate levels of genetic variation and population differentiation in R. cathartica in its introduced range in North America compared with its native range in Europe to better understand patterns of spread. By analyzing introduced and native populations using microsatellite markers, we found that introduced populations generally exhibited similar or slightly lower levels of genetic variation compared with native populations, consistent with a slight bottleneck effect. Introduced populations contained many different genotypes, indicating genetic admixture, rather than one or few genotypes. In a few cases, populations had been misidentified in the field and were glossy buckthorn ( Frangula alnus Mill.; syn. Rhamnus frangula L.). Overall, there was no substantial genetic differentiation detected between native and introduced populations of R. cathartica . Invasive spread in this species is likely due to its past horticultural history as well as adaptive biological traits such as competitive behavior, potential allelopathy, and seed dispersal via birds.