Current Issue (86-2)

Natural and Cultural History of Xanthorhiza simplicissima

Yellowroot (Xanthorhiza simplicissima Marshall, Ranunculaceae) is a low-growing deciduous shrub native to hardwood forests in the eastern United States. This review synthesizes existing knowledge about yellowroot’s natural and cultural history including traditional uses, contemporary applications, and future implications. Emphasis is placed on the southern Appalachian mountain region, which is the core of its cultural importance. Natural history and ethnobotanical knowledge about yellowroot were collected from published literature, oral histories, and field observations. While it was first described by botanists in the 18th Century, yellowroot was already a well-established and culturally significant plant to the Native peoples of southern Appalachia for centuries. At least 34 Indigenous medicinal and craft uses are documented, confirming that yellowroot was, and to an extent still is, a culturally significant plant for Indigenous people in the southern Appalachian region. European and African American settlers to the region also incorporated the plant into many of their folk traditions, and wild harvesting and cultivation continues to this day. Modern analytical techniques have identified key phytoactive compounds in yellowroot extracts, lending credence to its traditional medicinal uses and potential applications in modern medicine.

Modeling Habitat Suitability for Stewartia ovata Across the Southeastern United States

Mountain stewartia (Stewartia ovata) is a rare shrub or small tree endemic to the higher elevation regions of Georgia, Tennessee, and Alabama with isolated populations occurring in Kentucky, North Carolina, South Carolina, Virginia, and Mississippi. The species is often misidentified or overlooked by land managers and conservationists. As a result, mountain stewartia’s habitat and distribution descriptions are limited for restoration and conservation use. Modeling a species’ habitat suitability has become a critical first step in conserving rare and imperiled plant species. These models allow conservationists to locate previously undocumented populations and prioritize populations and habitats for conservation. This study presents a habitat suitability model for mountain stewartia across its known natural range based on maximum entropy (Maxent) modeling with nine environmental predictor variables and 60 occurrences from herbarium records (n=22), research-grade iNaturalist observations (n=25), and other author identified locations (n=3). The resulting habitat suitability map was classified into bins for spatial analysis. A total of 376,030 ha (0.44% of the study area) was designated within the top tier bin with the highest suitable habitat. Further, 133,344 ha (0.16% of the study area) of the top bin was found on publicly owned lands, indicating approximately 35.56% of the highest habitat suitability occurs within public lands. The presented model could allow plant conservationists to prioritize areas for conservation, reintroduction, and may lead to the discovery of previously undocumented populations.

Vascular Flora of the Christmount Preserve, Buncombe County, North Carolina

The Christmount Preserve is a botanically diverse and ecologically rich area of approximately 155 ha of southern Appalachian forest held in conservation easement. We conducted a floristic inventory of the preserve to inform conservation efforts on the property. Although the plant diversity within the preserve is an important attraction for residents and visitors, information on its flora is limited. This study builds upon a brief but informative 1996 report of the North Carolina Natural Heritage Program summarizing the preserve’s attributes as a natural area. A total of 317 specimens of vascular plants were collected during 2018–2020 to develop a vouchered flora of the preserve. These specimens documented 221 species in 165 genera and 84 families, 4.5% of which are not native to the Appalachian Mountain region. We found three plant taxa that are listed by the North Carolina Natural Heritage Program: Coreopsis latifolia, Hypericum buckleyi, and Robinia hispida var. fertilis. Plant community types found on the property include large areas of Rich Cove Forest, Acidic Cove Forest, and Montane Oak-Hickory Forest, but also included small patches of Pine-Oak/Heath–High Elevation Subtype, a globally imperiled plant association, along the high ridgelines. The information presented here will be used to help guide management efforts as well as educational programming by the managing organization, Christmount Christian Association (CCA).

Reevaluating Genetic Diversity and Structure of Helianthus verticillatus (Asteraceae) after the Discovery of New Populations

Determining population genetic structure of isolated or fragmented species is of critical importance when planning a conservation strategy. Knowledge of the genetic composition and differentiation among populations of a rare or threatened species can aid conservation managers in understanding how, and which, populations to protect. The whorled sunflower, Helianthus verticillatus (Asteraceae), is a federally endangered sunflower species endemic to the southeastern United States. The distribution of the species comprises four known populations within three states: Alabama, Tennessee, and Georgia. Recently, new populations were discovered in Marshall County, Mississippi, and Franklin County, Virginia. Here, we carry out a population genetic study of these new populations using nuclear microsatellite markers and compare our results to those from previously known populations of H. verticillatus. Our results show that both newly discovered populations contain novel genetic variation, with Mississippi containing the most private alleles out of all populations tested. The Virginia population is genetically similar to the previously known populations but is under the most conservation concern given the recovery of only two unique genetic individuals found in this population. These results indicate these new populations are worthy of protection and conservation efforts given the unique genetic variation they harbor.

New Populations of the Rheophytic Macrophyte Podostemum ceratophyllum Michx. (Hornleaf Riverweed) in West Virginia

Podostemum ceratophyllum (Hornleaf riverweed) is a macrophyte that inhabits swift-water rivers with stable substrates and abundant light in montane and piedmont ecoregions of eastern North America. Within these habitats, P. ceratophyllum is considered a foundation species because the plant can strongly influence community structure by increasing habitat complexity for macroinvertebrates and fishes, and facilitates resources cycling via elemental sequestration, herbivory, and detrital pathways. Currently, the USDA and NatureServe recognize P. ceratophyllum as a conservation concern in some states, but the plant’s status remains uncertain in many other states. In West Virginia, P. ceratophyllum is considered imperiled (S2) by the West Virginia Natural Heritage Program. The most recent records were collected in 1998, while other populations have not been confirmed since the late 1800s. To expand our current understanding of the distribution of P. ceratophyllum in West Virginia, we surveyed six historical sites and 34 new sites between 2015–2019. Four historical sites were found to still support P. ceratophyllum, and 10 new populations were discovered in six different river systems; however, P. ceratophyllum was not found at 26 other sites surveyed. Identifying new populations of P. ceratophyllum and resurveying previously documented populations in West Virginia expands the ecological and botanical understanding of this notably underreported plant. Improved documentation of P. ceratophyllum in West Virginia may benefit river management and restoration efforts in the state and provide insight into the plant’s sensitivity to anthropogenic disturbances.

A Review of Avian Dispersal of Non-Native and Invasive Plants in the Southeastern United States

Non-native and invasive (NNI) plants have spread throughout the southeastern United States. To monitor the spread of NNI plants and implement appropriate management we need to understand the relationship between NNI plants and their avian dispersers. Birds are the primary disperser of many NNI plants, and thus a thorough understanding of their role can aid agencies wishing to control the spread of NNI plants. We examined the literature to assess the current knowledge of the relationship between NNI plants, specifically shrubs, trees, and vines, and their avian dispersers in the southeastern United States. We found 56 papers covering 28 NNI plant species and 46 bird species. 66% of papers on NNI plants did not connect plants with specific avian dispersers and those that did tended to mention fewer than five avian species. More studies were conducted in Florida than any other state and most papers focused on the spread of NNI plants. Our review indicates a need for further research to identify the avian dispersers of NNI plants and the role they play in the spread of NNI in the southeast.

An Inventory of a Private Property Illustrates Diverse Cryptogam Floras in North Central Texas

The cryptogamic flora has remained unexplored in much of Texas and here we report 49 bryophytes (mosses, liverworts, and a hornwort) and 180 lichen-forming and allied fungi from a small private property in North Central Texas. Of the 229 species reported, 30 lichen-forming fungi (lichens) are here reported for the first time in Texas. Moreover, 76 of all taxa collected are represented by 10 or fewer specimen records in the state. Therefore, one out of every three species collected for this study represents a novel documented occurrence for a taxon belonging to poorly known and ecologically important groups of organisms. These results highlight the efforts of continuing to document cryptogam species throughout Texas and how cooperation with private landowners can contribute to novel biodiversity studies.

Scientific Note: Hydrochory in Sabal minor (Arecaceae)

The current cycle of global warming has contracted some range restricted species while concurrently expanding the range of more adaptable species. Sabal minor is a member of Arecaceae, the palm family, and is confined to lower latitudes in both western hemispheres. Latitudinal limitation of S. minor is believed to be related to low temperature intolerance. However the exact mechanism remains elusive. In this study reproductive fecundity of anthropogenically introduced populations in southern Virginia Beach, Virginia, was evaluated. Diaspore viability, approximated by floatability of fruits, was used to evaluate distribution by hydrochory. This study also documents a previously unidentified condition of fungal mass growth around the fruits of S. minor during buoyancy testing and suggests some areas for additional investigation.

Noteworthy Collection: Florida

This collection represents the southern limit of the North American distribution, north of Mexico, of Saggitaria platyphylla.

Three Non-Native Vascular Plant Species New to the Flora of Alabama

Three species of non-native vascular plants are reported here as new to Alabama. Persicaria capitata (Buch.-Ham. ex D. Don) H. Gross, Pistacia chinensis Bunge, and Sedum diffusum S. Watson are all species cultivated as ornamentals, and likely represent escapes from nearby plantings.

Scientific Note: Capsule-Seed Allometric Relationships in Ludwigia ravenii (Onagraceae), a Critically Imperiled Wetland-Obligate

Ludwigia ravenii is a critically imperiled tetraploid known historically from Virginia to Florida. There have been no published studies examining the number of seeds produced per capsule to guide researchers and conservationists in planning studies or collection efforts. Such data are important considering current guidelines by the Center for Plant Conservation recommend that no more than 10 percent of a population’s seed production be collected in a single season. To fill this void, our objective was to examine and report on capsule-seed allometric relationships in the species. Our study is based on 25 capsules from six plants from the North Carolina Coastal Plain. Though admittedly limited in geographic scope, we focused on these wild plants to avoid destruction of herbarium specimens and as they were already the subject of a broader, permitted inquiry into seed germination. Consistent with prior, range-wide monographic study, measured capsule dimensions were: length 2.87–5.41 mm (mean=3.98, sd=0.64); broader facet width 1.95–3.67 mm (mean=2.94, sd=0.43); narrower facet width 1.88–3.27 mm (mean=2.70, sd=0.39). The mean number of seeds produced per capsule was 304.8 (sd=94.9). The mean number of seeds produced by capsules at least 4 mm long was 361 (sd=65.7), whereas the mean number of seeds produced by capsules less than 4 mm long was 233 (sd=77.8). In the absence of additional data from other populations, we preliminarily recommend that capsule collection efforts focus on capsules at least 4 mm long.

Phylogenetic placement of Trifolium kentuckiense (Fabaceae), a new member of the native eastern North American clover clade

In 2013, a new species of clover endemic to Kentucky was described. This species, Trifolium kentuckiense (Fabaceae), has yet to be placed in a phylogeny but is hypothesized to be most closely related to T. reflexum based on morphology. We present phylogenetic evidence from the nuclear (ITS) and plastid genomes (trnL and ndhA introns) that T. kentuckiense is a member of a clade of seven Trifolium species native to eastern North America. Within this clade, T. kentuckiense is strongly placed in a clade with three other annual/biennial Trifolium species (T. bejariense, T. carolinianum, and T. reflexum); it is sister to T. reflexum, although support for this relationship is weak. Our results support previous findings that suggest the ndhA intron is much more variable than the trnL intron in the Eurosid I clade. The ndhA intron contained over twice the number of parsimony informative characters when compared to the trnL intron, though ITS was more variable than either region. We also provide a dichotomous key to native and nonnative members of Trifolium for Kentucky and its surrounding states. We suggest determinations of historic specimens of Trifolium, particularly those identified as T. reflexum, be reassessed to obtain localities that may still support populations of this recently described species. We also provide guidance on when and in what habitats to search for new populations of this extremely rare taxon.

Scientific Note: Loblolly Pine Traumatic Resin Ducts Serve as Indicators of Cool-Season Weather Events at Nags Head, North Carolina

We present a method for recording cool-season (mid-October–May) weather events near Nags Head, North Carolina. Standardized traumatic resin duct frequency (TRDsf) formations in loblolly pine (Pinus taeda L.) were determined from earlywood radial growth samples using the number of traumatic resin ducts that occur in response to stressful weather events. Based on a sample of 39 cores collected at Nags Head Woods Ecological Preserve during summer 2020, we tested if the occurrence of traumatic resin ducts in the earlywood was caused by late-season tropical cyclones, mid-latitude windstorms, and snow/ice storms and served as a proxy for extreme weather frequency during 1950–2019. TRDsf was significantly related to years that had at least one documented cool-season weather event. The average TRDsf in a non-storm year was 1.95 while the average for a storm year was 2.99. Further, TRDsf was correlated with the number of cool-season weather events and there was no tree age-related bias to storm-event detection. These results support using TRD frequency to reconstruct cool-season storm history beyond current climate records at locations where older (150+ years) stands of loblolly pine forests exist along coastal North Carolina.

2022 Elizabeth Ann Bartholomew Award Nominations

Elizabeth Ann Bartholomew (1912-1985) served as the Secretary of the Southern Appalachian Botanical Club from 1946 until 1981. Her life was devoted to plants, and she transferred her interest in plants and nature to students of all ages and walks of life. The Southern Appalachian Botanical Society annually presents the Elizabeth Ann Bartholomew Award in memory of her untiring service to the public, to plant systematics, and to this organization. This award was established in 1989 and has been presented to individuals who have also distinguished themselves in professional and public service that advances our knowledge and appreciation of the world of plants and their scientific, cultural, and aesthetic values, and/or exceptional service to the society.

2021 Reviewers

The Editorial Committee gratefully acknowledges the following people who reviewed manuscripts for Castanea in 2021