Current Issue (85-2)

Remnant American Chestnut (Castanea dentata) Near the Historical Western Range Limit in Southwestern Tennessee

The American chestnut (Castanea dentata) was once widespread in eastern North America and an ecologically important hardwood tree of deciduous forest communities prior to its near-eradication by chestnut blight (Cryphonectria parasitica). Remnant populations occur across much of its historical range, especially in older forests of the Appalachians and northeastern U.S. However, broad swaths of the southwestern portion of the species’ historical range remain poorly documented, potentially limiting the representation of genetic variation important for local adaptation in restoration efforts. Ongoing discovery and life-history characterization efforts for remnant C. dentata remains a priority to better understand the distribution and ecological status of this once important species, while identifying potential genetic sources of locally adapted or blight resistant trees. Here, we report the discovery of 22 C. dentata at four sites in southwestern Tennessee, adding novel observations that extend the range of known extant occurrences to the extreme western edge of the historical distribution in Fayette County. These observations include potentially reproductive individuals that should be revisited to assess reproductive and blight status, and that should be evaluated for current germplasm collection and restoration efforts.

Floristic Inventory of the James River Park System, Richmond, Virginia

We completed a floristic inventory of the James River Park System (JRPS), a ca. 223-hectare (550- acre) multi-unit park along the James River in Richmond, Virginia. The JRPS includes land within the riparian zone along a 13-kilometer (8-mile) stretch of the river that bisects the city, providing two million annual visitors with recreational access to the rapids along the “Falls of the James.” Although the vegetation within the park system is an important attraction for park-goers, information on the flora of the JRPS and this section of the James River corridor is limited. This study updates partial records of the JRPS flora from ca. 50 years ago with collections that were made over the span of three growing seasons from 2016–2018. A total of 566 species and sub-specific taxa were documented from 336 genera and 115 families, including 63 new botanical records for the locality. Native species comprise 69.4% of the overall species richness, with dominant families including Asteraceae, Poaceae, and Cyperaceae. Non-native invasive species are prevalent throughout the park: 51 species are listed on the Virginia Invasive Plant Species List, 21 of which carry a “high” invasiveness rank. Four state-listed rare species were documented within the park, and seven other state-rare “watchlist” species were found. The information presented here is being used to help guide management efforts of the JRPS Invasive Plant Task Force, an organization dedicated to the removal of non-native invasive species, restoration of natural habitats, and preservation of natural communities within the park system.

Plant Community Response to Hydrologic Restoration in the Great Dismal Swamp

Peatlands in the mid-Atlantic outer coastal plain region contain obligate hydrophyte species which were harvested and replaced by facultative tree species. The Great Dismal Swamp was drained from the colonial era until 1974, when water levels were partially restored. In September 2013, further restoration consisting of two large weirs followed extensive peat-burning fires. This study evaluated depth-to-water-table and vegetation structure both prior to and following weir operation. Wells were installed and depth-to-water-table was recorded continuously from 2013 to 2015 within six of the 15 forested stands where vegetation species dominance was quantified for tree, shrub, herb, and vine strata. Following weir installation in 2013, water tables rose an average of 28.08 cm in 2014 and 32.69 cm in 2015, during the June–July peak of the growing season. Most water levels were too low to meet the federal regulatory indicator of wetland hydrology or the seasonally flooded, saturated hydrologic regime typical of peatlands. After restoration, species dominance and frequency, as well as metrics based on hydrophyte dominance and floristic quality in study plots, were unchanged. Ordinations detected no directional shift in plant community composition among pre- and post-weir periods. Although insufficient time may have passed for shifts in plant communities, additional increases in water level above those reported here appear necessary to restore a pre-disturbance hydrologic regime and plant community structure. However, above some threshold water level, planted trees will exhibit increased mortality and limit reestablishment.

Noteworthy Collection: Florida

Xyris correlliorum, a rare species endemic to Highlands County, Florida, had not been seen there since 1996. This collection confirms that X. correlliorum is extant. Relevant aspects of this plant are also documented.

The Complete Plastid Genome of Neottia bifolia (Raf.) Baumbach (Orchidaceae): Insights Into Chlorophyllous and Achlorophyllous Plastid Genomes

Neottia bifolia is a small, terrestrial orchid distributed across the southeastern United States and northward up the Atlantic coast into Canada. The genus is well-studied as a model for the evolution of mycoheterotrophy, having both chlorophyllous and putatively achlorophyllous taxa. Despite this, the photosynthetic species, N. bifolia is relatively understudied. We provide results from the sequencing, assembly, and annotation of the complete plastid genome of N. bifolia and examine some evolutionary trends in the genus, using the 10 additional complete Neottia plastid genomes available on GenBank. We find that the plastid genome of N. bifolia is 156,533 base pairs in length with 130 protein-coding genes, including 38 tRNA genes and eight rRNA genes. We find a similar number of rRNAs and tRNAs across the genus, but significantly fewer protein coding genes and an overall smaller plastid genome size in the mycoheterotrophic species. We find support for the monophyly of the mycoheterotrophic species. The placement of N. bifolia varies slightly between inferences, but the species is most frequently placed in a clade with Neottia cordata, Neottia japonica, and Neottia suzuki.

A New Species of Clinopodium (Lamiaceae) from Alabama

Clinopodium talladeganum B.R. Keener & Floden is described as a new species from the Talladega Mountains, Alabama, United States. Morphological differences were compared and analyzed using PCA which supported it as a distinct morphological cluster when compared to the sympatric C. georgianum. An updated key to the genus is provided for the southeastern United States.

Mentzelia oligosperma Nutt. (stickleaf, Loasaceae), Distribution and Abundance in Illinois

We conducted field searches for populations of Mentzelia oligosperma Nutt. (stickleaf) throughout the known range of this species in Illinois during the growing seasons of 2010–2019. A species common to the prairies and plains of western North America, it is habitat-specific and rarely observed in Illinois. Populations are confined mostly to narrow limestone cliff ledges along the bluffs of the Mississippi River in Adams, Calhoun, Monroe, Pike, and Randolph counties on the western border of the state. We identified 18 potential stickleaf sites based upon herbaria searches and interviews with biologists. Subsequent field investigations determined the presence of 15 extant sites, including two new locations at Hull in Pike County and the Fults Hill Prairie Annex in Monroe County. Five historic populations are extirpated. The state total of 498 plants represents populations ranging from six to 85 individuals at 15 sites, with most locations having fewer than 20 individuals. Stickleaf is currently listed as endangered by the Illinois Endangered Species Protection Board due to its restricted habitat and low population densities.

Noteworthy Collections: North Carolina

We report seven collections of upright chickweed, Moenchia erecta (Caryophyllaceae), from Guilford County, North Carolina. These appear to be the first reports of this species in the state, the first collections in the southeast since 1958, and the first collections east of the Mississippi River since 1993.

Noteworthy Collections of Four Non-native Vascular Plant Species New to the Flora of Alabama and One Species Rediscovered After 125 Years

Four species of vascular plants are reported here as new to Alabama: Geranium texanum, Gloriosa superba, Prunus yedoensis, and Trifolium echinatum; and one species was rediscovered after 125 years, Momordica charantia. The Prunus yedoensis record represents the first collection of this species from the Southeastern United States. The Gloriosa superba record is the first for this species outside of Florida. Based on habitat, population size, and/or previous collections, all of these taxa are considered to be introduced in the flora of Alabama.

Changes in Herbaceous Species Variables After Enhanced Hunting Effort for White-tailed Deer in Soldiers Delight Serpentine Ecosystem in Maryland

Soldiers Delight Natural Environment Area and Wildlands, a biodiversity hotspot in the Maryland piedmont, conserves an endangered serpentine oak savanna (“barren”) ecosystem with numerous rare, threatened, and endangered species. White-tailed deer became conspicuous during daylight hours circa 1994. In 2008, a helicopter-mounted forward-looking infrared camera (FLIR) survey estimated 36 deer/km2 (93 deer/mi2). A sharpshooter harvest was conducted in 2014, and public hunting was expanded beginning with the 2014–2015 season. This study investigated changes in percent cover, frequency, and importance percentage of herbaceous species using site data collected in 1993 and 1994 when deer were becoming conspicuous, in 2011 when deer density was extremely high, and in 2018 and 2019 after four to five years of expanded hunting effort. In addition, the level of impact to serpentine aster (Symphyotrichum depauperatum), an endangered serpentine endemic, was quantified using caged and uncaged plants. Gray goldenrod (Solidago nemoralis), common in 1993 and 1994, occurred in only one of the 37 plots in 2011 and none in 2018 and 2019. Serpentine aster had almost disappeared from all plots by 2011, but in 2019 was within 50% of 1993 mean percent cover levels. Number of flower heads and main stem length of serpentine aster were significantly different between caged and uncaged plants, except during the three years following the sharpshooter harvest. Data indicate that deer herbivory will continue to be excessive with only regulated public hunting. To prevent species extirpation, public hunting will need to be supplemented by additional deer reduction.

Portulaca amilis

Noteworthy Collections: First Record of the Non-native Plant Portulaca amilis (Portulacaceae) in Tennessee

We report the first record of Portulaca amilis in Tennessee. A native of South America, P. amilis is a weedy plant that has been introduced to and naturalized in the southeastern United States. Previously this species has only been reported from the Atlantic Coastal Plain and Piedmont. This suggests a range expansion either west over the Appalachian Mountains from the Carolinas, or north from Georgia, Alabama, or Mississippi into the Ridge and Valley region of east Tennessee.


The Flora of a Mesic Forest Remnant in Iowa’s Paleozoic Plateau: Malanaphy Springs State Preserve (Winneshiek County, Iowa)

We present the results of a floristic inventory and qualitative descriptions of the forest communities occurring in Malanaphy Springs State Preserve (MSSP), located in the Paleozoic Plateau of northeastern Iowa. Most of the 25.9-ha preserve is a mature mesic to dry-mesic deciduous forest community occurring on a steep slope adjacent to the Upper Iowa River. The preserve also contains a small floodplain forest as well as a small highly disturbed forest on the upland. We documented 422 plant taxa in our surveys, including 52 non-vascular taxa, 14 seedless vascular taxa, 3 gymnosperms, and 353 angiosperms. Eighty-seven percent of the vascular plant taxa are native, and 21% of the species have an Iowa coefficient of conservatism score of 7 or higher. Five species are listed by the Iowa Department of Natural Resources as endangered, threatened, or of special concern in the state. This survey provides critical baseline data needed to document future changes in the plant communities of MSSP. We conclude that this preserve is an important example of high-quality mesic deciduous forest communities in Iowa. We further conclude that the species diversity of the preserve is threatened by the cumulative impacts of habitat loss, high levels of deer herbivory, invasive species, nitrogen deposition, and climate change and that active management and strategic policy decisions will be needed to preserve native plant species diversity.

Flora of the Forest at Mountain Lake Biological Station, Giles County, Virginia

Local floras are a basis of biogeography, ecology, evolution, and systematics, and they add value to research sites. Mountain Lake Biological Station is located between 1,150 and 1,319 m elevation in southwestern Virginia on infertile, acidic soils supporting a second-growth forest strongly dominated by Quercus rubra about 150 years old. We sampled vascular vegetation on 352 randomly distributed plots 10m in diameter with 8 subplots of 1 m2 each. The plots contained 175 taxa (including 7 taxa that included 16 lumped species); other fieldwork added 43 species for a total of 227 species in the forest. We excluded disturbed areas around buildings, roadsides, and ponds that harbor many ruderal and invasive species. Average detection probability of a species on a plot was estimated to be 75%. We recorded binary occurrence (present or absent on a plot) and prevalence (occurrence on 0, 1, 2, … 8 subplots per plot) and a set of environmental variables measured in the field or laboratory, or estimated from LIDAR data collected by NEON. Nonmetric multidimensional scaling ordination rejected the null hypothesis of random distributions of herbaceous species among plots. Cluster analysis defined eight groups of plots based on prevalence of herbaceous species to illuminate rejection of the null hypothesis. The environments of these clusters, determined only by their floras, demonstrated the importance of rock type, soils, solar radiation, canopy height, and topography in determining the local distribution of species. Significant differences among assemblages and their environments occurred within a superficially homogeneous forest.

Genetic Diversity and Population Structure of the Forgotten Geum, Geum geniculatum Michx.

Geum geniculatum (Rosaceae), bent avens, is a perennial herb restricted to the high elevations of three mountaintops near the North Carolina/Tennessee border (USA). Although geographically restricted, occurrences on these mountaintops can have up to hundreds and occasionally thousands of individuals. While Geum geniculatum has been censused thoroughly, some sites have not been visited in over a decade, and formal biological studies are lacking. To understand genetic variation within the species and connectivity among populations, individuals were sampled from each of three extant mountain locations and were genotyped using 14 microsatellite markers previously developed for other congeners. Results show that G. geniculatum displays high genetic diversity, and that each mountain acts as a highly structured metapopulation with moderate interpopulation differentiation. Based on the high numbers of private alleles and results of an M-ratio test, genetic drift is likely driving structure and differentiation among metapopulations. Results will inform management of the species, and suggest that transfer of seeds or genetic material among sites should be minimized.

Reviewers 2020

We thank all of those who have served as reviewers of articles submitted to Castanea.