Volume 91 – Issue 1 (May 2026) – The Southern Appalachian Botanical Society

Scientific Note: Here the Whole Time: A Revised Understanding of White Alumroot (Heuchera alba, Saxifragaceae) in the Susquehanna River Valley

Anais Barnes
Maddie Wickers, Tanisha M. Williams, Scott Schuette, Ryan A. Folk, and Christopher T. Martine
2026-05-31T00:00

Heuchera alba and H. pubescens (Saxifragaceae) are closely related species of alumroot endemic to the Appalachian region of eastern North America that can be difficult to distinguish morphologically. Heuchera pubescens has been understood to occupy a range from Kentucky to Pennsylvania, with the distribution of H. alba restricted to Virginia and West Virginia—plus a recently-recorded extension into Pennsylvania discovered with the help of social media. The uncovering of H. alba in Pennsylvania has challenged historical perceptions of Heuchera distributions in the state, particularly as this relates to the current concept of H. pubescens which may be in need of revision. The present survey of Heuchera conducted in Susquehanna River Valley finds that all previous records of H. pubescens in the valley are instead attributable to H. alba. Additionally, collections of pollinators at these sites beginning in 2019 established the frequent presence of a specialized pollinator, the alumroot cellophane bee (Colletes aestivalis)—the first state record of this bee in Pennsylvania in over a century. Possible reliance of a network of disjunct plant populations in narrowly-defined habitats on an oligolectic bee for pollination services suggests that assessing the population genetics of H. alba in Pennsylvania is an important future step.

Distinct Features of an Imperiled Habitat that Supports the Endemic Bartonia paniculata subsp. texana in Southeast Texas

Sharandeep Singh Chahal
Robert D. Cox, Jason Singhurst, and Jyotsna Sharma
2026-05-31T00:00

Bartonia paniculata subsp. texana is an endemic, imperiled plant occurring within the baygalls (i.e., forested seep bogs) of the West Gulf Coastal Plain Forested seep (Southern Type; WGCPFS- ST) habitats of Southeast Texas, which are also considered rare plant communities. The number of individuals and populations have both declined by 50% over the last 57 years. Yet, niche preferences within the WGCP-FS-ST of B. paniculata subsp. texana are not characterized, which could enable targeted surveys to identify additional populations and to restore degraded habitats. We investigated whether plant communities and environmental conditions within baygalls that support B. paniculata subsp. texana were distinguishable from locations that do not support the taxon, to guide future surveys and conservation efforts. Baygall habitats within the WGCP-FS-ST region of Southeast Texas were surveyed. We compared vegetation composition, canopy openness, ground cover, and soil properties between baygall sites that consistently support B. paniculata subsp. texana and those that do not. Our results indicate that B. paniculata subsp. texana prefers narrow niches within its baygall habitat. These areas are characterized by distinguishable understory vegetation composition (Shannon-Wiener Index=1.4, Simpson Index=0.62), canopy openness (16%), ground cover (live vegetation=68%, debris=11%, bare soil=30%), and soil moisture (23%) as compared to bay-galls that do not consistently support the taxon. However, overstory vegetation and soil physicochemical properties between occupied and unoccupied sites were similar. The presence of B. paniculata subsp. texana is associated with specific understory vegetation and microhabitat conditions. These findings provide valuable criteria for identifying additional populations and prioritizing areas for habitat restoration.

Vascular Flora of Bark Camp Barrens WMA, Coffee County, Tennessee

Quinn Towery
Todd Crabtree and Joey Shaw
2026-05-31T00:00

A vascular plant inventory of Bark Camp Barrens Wildlife Management Area, Coffee County, Tennessee, was performed over the 2023 and 2024 growing seasons. The site was a 1,395 ha area located 10 km east of Manchester, Tennessee, in the Barrens region of the Eastern Highland Rim. A total of 875 specimens were collected, resulting in the inventory of 698 species and lower taxa from 349 genera and 127 families. Two species found at Bark Camp Barrens Wildlife Management Area were considered G1 or G2, 35 species were listed on the Tennessee Rare Plant List, and 104 species were considered S1 or S2. This is the first known comprehensive floristic survey in the Barrens Region of Tennessee’s Eastern Highland Rim.

Noteworthy Collections: Aquatic Flora of Mississippi

Samuel A. Schmid
J. Nicholas Engle-Wrye and Gray Turnage
2026-05-31T00:00

Reported here are five collections of four rare, aquatic plant taxa in Mississippi that were collected as part of routine surveys of Mississippi’s freshwater ecosystems. Voucher specimens reported here were deposited at the Mississippi State University (MISSA) herbarium, with duplicate material deposited at the L.H. Bailey Hortorium (BH) at Cornell University. These collections help expand our understanding of the native aquatic biodiversity of Mississippi, as well as serve as a record of early detection for an introduced taxon of concern: Vallisneria ×pseudorosulata.

Effects of Cold-stratification and Light on Seed Germination in Critically Imperiled Ludwigia ravenii (Onagraceae)

Alexander Krings
Adam Miller
2026-04-30T17:45

Ludwigia ravenii (Onagraceae) is a critically imperiled wetland-obligate, apparently now limited to anthropogenic habitats in Virginia and the Carolinas. Historical collections are also known from pond margins, shaded creeks, bogs, and swamps, as far south as Florida. Gaining knowledge about seed germination requirements is crucial for developing efficient ex situ propagation methodologies. The objective of the present study was to analyze the effects of cold-stratification and light on the germination of seeds of the species. Using a 4 × 3 factorial design, seeds sourced from plants derived from a North Carolina Coastal Plain population were assigned to either no cold-stratification (c-s), 30-day c-s, 60-day c-s, or 90-day c-s, and to one of three light treatments during germination in a growth chamber (0% shade, 40% shade, or 90% shade). Overall, >14,000 seeds of the species were involved in the study. Two-way ANOVA found a significant effect of c-s treatment (p<0.001), percent shade (p<0.001), and their interaction (p<0.001) on mean percent germination. The highest mean cumulative percent germination was achieved by seeds in the following treatments, none of which differed statistically: 30-day c-s/0% shade, 60-day c-s regardless of shade treatment, and 90-day c-s/0 and 40% shade. Seeds not cold-stratified exhibited the lowest mean cumulative percent germination at the end of the 30-day monitoring period (3.7–32.7%), regardless of shade treatment. Based on our results and for similar growth chamber conditions, we recommend 30- or 60-day c-s followed by unshaded germination for ex situ growing programs.

Pictures of flowers and fruits of Ludwigia ravenii

Coefficients of Conservatism for the Vascular Flora of Tennessee and Kentucky

Sevyn Brothers
Joey Shaw
2026-04-30T17:40

Floristic Quality Assessments (FQAs) are used as indices of ecosystem quality and typically consist of two parts, a species checklist and each species’ coefficient of conservatism, or c-value. Tennessee and Kentucky (TNKY) share most native and naturalized vascular plant species and ecoregions, putting TNKY in position for combined c-value assignment. Previously, two TNKY botanists created individual draft c-value assignments for TNKY’s flora. One assigned c-values to 100% of the documented vascular plant species of the states of Kentucky and Tennessee at the time the work was performed and the other to 98%; thus, these two botanists overlapped on assigning c-values to 98% of the TNKY flora. Two previous attempts by Shaw assembled panels of TNKY botanists for c-value assignment. Although neither attempt resulted in statewide c-values, these twelve botanists assigned c-values to 35% of TNKY’s flora. Additionally, we used two existing databases, (43% and 76% of TNKY’s flora, respectively), each treated as “a botanist,” to assemble a “panel of experts.” Although using a panel to assign c-values is most common, here we show that using a combination of a botanist panel and supplemental databases is an effective means of c-value assignment. We conducted statistical analyses to test correlation of botanists’ c-value assignments and TNKY’s native c-value data against the floras of six surrounding states, and we held a public review period of three months. Overall, c-values were successfully assigned to 99% of TNKY’s flora (3,360 species).

Volume 91 – Issue 1 (May 2026)