Illinois is home to approximately 2,107 native plant species of which about 16% are listed as threatened or endangered (T & E). In addition to the common threats associated with the decline of these species, climate change is a rapidly emerging threat. Climate predictions for Illinois have estimated that summer temperatures will resemble present-day summers in Texas by mid- to late-century, while precipitation patterns are less predictable. Using NatureServe's Climate Change Vulnerability Index (CCVI) tool we evaluated the climate change vulnerability for all 331 of Illinois T & E plant species. Overall, we found that over 80% are vulnerable to climate change. Barriers to migration are a leading factor associated with vulnerability in Illinois, where 97% of listed species are affected by anthropogenic barriers and 24% are affected by natural barriers. The sensitivity of species to changes in temperature, precipitation, and hydrology are also associated with vulnerability. The CCVI score was associated with most of the dozen or so other factors incorporated in the tool, though to a lesser degree. This study provides insights into the most vulnerable plant species in Illinois and provides much needed information to land managers, policy makers, and researchers. By highlighting which T & E species are most vulnerable to climate change, and what factors are most responsible for their vulnerability, this work will aid in prioritizing limited resources and developing adaptation strategies for them.

Red spruce (Picea rubens) is a long-lived tree species that thrives in cool, moist environs. Its ability to adapt to rapidly changing climate is uncertain. In the southern Appalachian Mountains, red spruce reaches its greatest abundance at high elevations, but can also occur across a range of mid and lower elevations, suggesting the possibility of a correlation between genetic variation and habitat. To assess clinal phenotypic variation in functional traits related to climate adaptation, we collected seed from 82 maternal sib families located along replicated elevational gradients in the Great Smoky Mountains National Park, TN (GSMNP) and Mount Mitchell State Park, NC (MMSP). The percentage of filled seeds and seed mass increased with elevation, indicating that successful pollination and seed development was greatest at the highest elevations. Seedlings sourced from GSMNP displayed a strong relationship between elevation and bud set when grown under common garden conditions. High elevation families set bud as many as 10 days earlier than low elevation families, indicating adaptation to local climate. Across parks, no effect of elevation was noted for bud flush. Our results demonstrate that red spruce in the southern Appalachian Mountains displays clinal variation in bud set that may reflect local adaptation to climate, although this varied between the two parks sampled. We suggest that genetic adaption of red spruce to different climate regimes, at both local and broad spatial scales, is in need of more intensive study, and should be carefully considered when selecting seed sources for restoration.

Seed mortality due to low winter temperatures has been proposed as an explanation for the lack of seedling recruitment in natural populations of the rare riparian species Alnus maritima, but other factors such as the absence of essential root symbionts or canopy clearing disturbances could also limit establishment of new individuals. We investigated whether any of these factors could be identified as preventing recruitment into existing seaside alder populations. Stratification studies showed that not only can seeds withstand low temperatures, longer periods of cold stratification promote earlier seed germination and expand the temperature range for germination. Root microbiome studies unexpectedly found that seedlings inoculated with the native microbiome prior to planting had lower survival compared to uninoculated individuals, and uninoculated individuals declined in survivorship after natural inoculation in the field. Canopy disturbance by burning or clipping vegetation promoted neither seedling growth nor survival initially, with seedling survival lower in burned plots due to the release of an aggressively growing competitor. Our results show that physiological stress by microbial symbionts and competition with other species are likely primary limiting factors—more so than seed mortality from low temperatures—and should be the focus of future conservation efforts.

Orchard Knob is a 2.5 ha National Military Park near downtown Chattanooga, Tennessee. This historic site protects a bubble of limestone glade and xeric limestone prairie habitat in an otherwise heavily developed, urban area. A floristic survey was conducted across two growing seasons, yielding 212 taxa across 152 genera and 58 families. Seventy-four non-native taxa were documented, about 35% of the total flora. Six rare, state-ranked species were documented: Baptisia aberrans, Clematis fremontii, Hypericum dolabriforme, Packera paupercula var. appalachiana, Symphyotrichum ericoides var. ericoides, and Viola egglestonii. An exploration of Civil War-era herbarium specimens and historical documents illuminated the historical flora of the site, and through the geolocation of herbarium specimens of select “indicator species,” the authors demonstrated that grassland habitats were once more abundant in the Chattanooga area.

Stone Mountain in DeKalb County, Georgia, is a large exposed granite monolith, 514 m (1,686 ft) above sea level and covering 230 ha (560 ac). This monadnock is located in the southwestern portion of Stone Mountain Park, comprising 1,300 ha (3,212 ac) owned by the state of Georgia. Recent specimen digitization efforts at the University of Georgia Herbarium (GA) have greatly facilitated capture of data from historic vouchers collected from this park. Based on these newly available data, the goals of this project were to (1) prepare a vouchered species list for the park, (2) produce a vegetation map based on georeferenced label data, and (3) identify all plant collectors and track collection activities through time and taxon focus. Eighty-one individuals and teams collected 1,207 vouchers (709 species) dated 1846–2011. The largest families were Asteraceae (96 spp.), Poaceae (70 spp.), Fabaceae (49 spp.), Cyperaceae (33 spp.), Rosaceae (21 spp.), and Lamiaceae (20 spp.). Approximately 17.5% of the species were exotic. Eighteen species are listed as rare in Georgia with state protection status conferred on five species; Gratiola amphiantha (threatened) and Isoetes melanospora (endangered) are also federally ranked. Specimen label data and various map resources were used to plot the locality of each specimen. Habitat data were recorded on 808 specimen labels, allowing assignment of 612 taxa to at least one of five general habitat types. GPS coordinates, assigned through GeoLocate, were combined with habitat data and infrared imagery to create a general vegetation map of Stone Mountain Park.

Marshallia mohrii (Asteraceae) is a perennial forb endemic to grasslands in the southeastern United States. Despite having been listed as federally threatened for three decades, little is known about its biology and life history. In this study, we examined the role of light, temperature, seed age, and cold stratification on seed dormancy break and germination in M. mohrii. We also quantified soil temperatures in a Ketona glade population of M. mohrii to infer dormancy breaking and germination phenologies under natural conditions. Relatively high proportions (>65%) of cold stratified seeds germinated across a range of temperature regimes in both light and darkness, whereas nonstratified seeds only germinated to high proportions in light at high temperatures. Germination proportions of laboratory stored seeds were slightly greater than freshly matured seeds, but remained much lower than those of cold stratified seeds. According to laboratory experiments, both autumn and spring germination phenologies are possible depending on the temperature and light conditions seeds experience after dispersal. Seeds of M. mohrii exhibited type 3 non-deep conditional physiological dormancy, which has been found in other members of Asteraceae from temperate grasslands. Overall, the germination niche of M. mohrii is defined by conditional seed dormancy, reduced dormancy levels following cold stratification, dark germination after dormancy loss, seasonal germination cueing, and seed traits consistent with short-term persistence in soil. Results from our study are useful for future conservation and recovery actions with M. mohrii and represent the first known published report of germination traits in this genus, which contains several other rare and range-restricted species.

The biodiversity of freshwater springs in the Arkansas Ozarks is poorly described and has received relatively little attention from researchers. Information on the biodiversity of springs is crucial for their management and conservation. This study describes the aquatic and semi-aquatic plant communities and key habitat features of several springs located at Buffalo National River, Arkansas. We report 58 taxa from among all springs, including eight genera of algae, one species of horsetail, three marchantiophytes, and one bryophyte. Among angiosperms, we found 21 species of monocots and 24 species of eudicots. Six non-native species occur among the springs and none are considered to be invasive. Data show that impounded springs tend to have higher plant diversity than springs with primarily lotic geomorphologies. Cluster analysis showed that the springs with a prominent lentic structure were most similar to each other with respect to shared taxa, while the springs with well defined, long spring-runs and no functional impoundments shared the most taxa. Geographic proximity in the watershed does not appear to play a substantial role in similarity of plant populations, indicating other factors are involved. An NMDS analysis of habitat and water chemistry data corroborated the cluster analysis and showed that habit structure plays a key role in plant community composition. Springs at Buffalo National River occurring within the Boston Mountains and Springfield Plateau appear to have lower taxonomic diversity compared to the larger springs occurring on the adjacent Salem Plateau, which is likely because of their low magnesium concentrations.

Gentiana autumnalis (pine barren gentian) is a rare, fall-flowering perennial that is endemic to pine barren habitat from New Jersey to South Carolina. This disturbance-adapted, early successional species is at risk in New Jersey as a result of human interactions, namely growing season mowing and fire suppression. We used a repeated measures design to compare the differences between managed (mowing and prescribed fire) and unmanaged G. autumnalis populations for density, life stage, mortality, and fecundity. Managed populations had a greater gentian density, proportion of reproductive individuals, and seedlings compared to unmanaged populations. Implementing prescribed burns and mowing at previously unmanaged sites prior to spring growth increased gentian density, flowering, and seed set the same year. Our data support that prescribed burning and mowing can be beneficial management tools for the conservation of G. autumnalis and other disturbance-adapted species that require open early-successional habitat. However, their implementation can have negative consequences if conducted during the growing season, especially for roadside populations that are periodically mowed. Declining rare plant populations have the potential to benefit from management practices that facilitate ideal growing conditions and influence life stage transitions that will best improve population growth rate over time.

The dwarf sundew (Drosera brevifolia) occurs from Uruguay to Virginia. Disjunct populations occur in the southeastern U.S. with the northernmost in Kentucky. Despite this wide distribution, relatively little is known about the biology of this species. It has been described as both annual and biennial. The endangered Kentucky population is considered biennial, but occasionally, live, mature plants have dead flower stalks in early autumn suggesting some may be perennial. In 2013, 40 sundews that germinated in the fall of 2012 were marked as they flowered in 2013. They were observed into a third growing season in 2014 until the end of July. Sixteen plants (40%) died after setting seeds in their second growing season, while nine (22.5%) remained alive, flowered, and set seeds again the following year. Seven of these were still alive at the end of July 2014. Fifteen plants were puzzling as the leaves were dead after setting seeds in their second growing season, but were alive May 2014, of which 12 flowered. This study confirms that at least a portion of the Kentucky population of D. brevifolia is perennial. This is probably facultative perenniality because some plants only survive to a third growing season when precipitation falls evenly over the growing seasons and when no hot, dry periods occur. Mild winters without extensive snow cover may contribute to facultative perenniality as well.

Chevreulia acuminata is reported for the first time in North America from recent collections in the southeastern United States. Populations from Lee County, Alabama, and one in Troup County, Georgia, were found growing in lawns or grassy areas along with other weeds. Photographs and a description of C. acuminata are provided.

Purple loosestrife (Lythrum salicaria) is documented for the first time for Louisiana in Plaquemines Parish, extending its range southward about 310 km. Three species of Lythrum are now known for Louisiana, and four species have been recorded for the central Gulf and lower Mississippi valley regions. A key to species and regional distributional data are provided for L. salicaria.

Geum radiatum is a federally endangered high-elevation rock-outcrop endemic herb that is widely recognized as a hexaploid and a relic species. Little is known about G. radiatum genetic diversity, population interactions, or the effect of past augmentations of populations. This study sampled every known population of G. radiatum and used microsatellite markers to measure genetic diversity and population structure. The analysis demonstrates that there is interconnectedness and structure among populations. In addition, the analysis was able to differentiate transplanted individuals and identify putative anthropogenically admixed individuals within augmented populations. Geum radiatum exhibits diversity within and among populations and current gene flow connects the northern populations. This information provides a greater understanding of the genetic sustainability of G. radiatum and what conservation efforts will most help this imperiled species to survive.

Thompson Pond, a bog lake in Pine Plains, New York, has flora indicative of both ombrotrophic and minerotrophic conditions. Distinct community types within this wetland system include a peripheral moat, hummock swamp, floating vegetation mats, peat rafts, aquatic floating-leaved and submergent macrophytes, and open water. A false-bottom of unconsolidated peat overlies the lake bed. Vegetation composition is typically diverse in such lakes, which support species of both acidic and calcareous habitat affinities. We repeated a 1973–74 survey to assess changes in wetland flora after four decades. The recent survey yielded 218 vascular plant species, representing 66 families and 134 genera. The largest genus was Carex with 26 species. Forty species from the original survey were not relocated, and 97 species were found in the recent survey that had not been found in the original survey. Eriocaulon aquaticum, usually associated with oligotrophic waters, was common in the original survey and not found in the recent survey. Aerial photos were used to calculate the change in vegetation cover, revealing that floating vegetation mats and peat rafts expanded between 1970 and 2016. Nutrient loading from agricultural and residential land use within the watershed, in addition to the installation of a dam across the lake's surface water outlet have likely contributed to the floristic and community structure changes seen in Thompson Pond.

American ginseng (Panax quinquefolius) roots have long been harvested for use in herbal medicine. Overharvesting has threatened long-term viability of wild American ginseng populations. Research has been ongoing to determine factors affecting the variation of ginsenosides in roots. Given the conservation concerns regarding wild American ginseng, we began experimenting with a partial-root harvest method in 2014 for extracting tissue for ginsenoside analysis without killing individual plants or causing long-term declines in wild populations. We took partial-root harvest samples from 57 plants in four wild populations throughout western North Carolina and monitored morphological attributes of these and 56 paired, unharvested plants of similar size for four years after harvest. Partial-root samples were taken from an additional 162 plants from 16 new populations in 2015 and 2016. Morphological attributes of these plants were monitored annually or biannually. In the paired plant study, annual reemergence did not differ between harvested and unharvested plants in any year after harvest. Leaf area was significantly lower in harvested plants than unharvested controls in the first year postharvest, but these differences did not persist after the first year. In the unpaired study, preharvest-postharvest comparisons were more variable, likely due to different harvest years and interannual variation in weather. Our results demonstrate that partial-root harvest could be an effective way for ginsenoside researchers to reduce their impact on wild and cultivated American ginseng populations and it may represent a non-destructive harvest protocol for root tissue phytochemical analysis.