Castanea Current Issue Volume 91 — Issue 2 (December 2026) – The Southern Appalachian Botanical Society

Survey of Disjunct Red Spruce (Picea rubens) Stands in North Carolina Mountain Basins

Caroline M. Tintinger
Nikita A. McClure, Paige C. Hannam, Jonas A. Hattman, Dalia Mouawad, Carter Patterson, Radmila Petric, Jason P. Love
2026-09-01

In the southern Appalachians, disjunct red spruce (Picea rubens) populations persist at low latitudes at elevations above 1,370 m. However, research on the condition of these disjunct red spruce populations is limited. This study compares species composition, stem density, basal area, health, and recruitment in two of the southernmost red spruce populations in North America: the Alarka Laurel and Rich Mountain spruce bog basins in Nantahala National Forest, North Carolina. Moreover, using stand data collected at Alarka Laurel in 2007, we assessed changes in the stand and compared those data to our 2022 survey. Our findings revealed that red spruce was the dominant overstory species, comprising 24.3–25.9% of all measured overstory trees, with seedlings and saplings making up 51.0–86.2% of the red spruce population, indicating stable recruitment. Red spruce basal area declined by 48.2% from 2007 to 2022 in Alarka Laurel, with a concomitant increase in some hardwood species. However, both Alarka Laurel and Rich Mountain showed levels of sapling and seedling recruitment that were comparable to red spruce stands found in other regions. Overall, red spruce trees were healthy, particularly seedlings, representing the healthiest size category, determined through visual assessment. Our results, derived from a reassessment of Alarka Laurel and the addition of the Rich Mountain site, suggest that these stands are relatively stable but may benefit from modest management efforts that increase light availability in areas with dense evergreen shrub cover or that have an overstory dominated by red maple (Acer rubrum).

Another Southeastern U.S. Endemic Rescued from Obscurity: Morphological and Molecular Evidence for the Recognition of Euphorbia apocynifolia

Mac H. Alford
Andrew C. Fennell, Daniel M. McNair, Johnathon P. Osborne, J. Richard Carter, Jr., Joey Shaw, Sabrina Y. S. Sewell, Heather M. Sullivan, John R. Gwaltney, Ki-Ryong Park
2026-08-27

Unusual individuals of the Euphorbia corollata (Euphorbiaceae) complex were encountered during field work in mature, closed-canopy, hardwood forests on limestone-derived substrate associated with the Jackson Prairie of Mississippi. Subsequent examination of herbarium specimens of Euphorbia from the southeastern United States yielded similar individuals from Alabama, Florida, Georgia, South Carolina, and North Carolina. Unlike the sympatric E. corollata and E. pubentissima, these individuals have longer petioles, broader leaves with pilose margins, smaller cyathia, different phenology, and occupy different habitats. To test species boundaries, morphological character dif-ferences were explored using principal component analysis (PCA), significant differences between groups were tested using multivariate analysis of variance (MANOVA) followed by Tukey post-hoc test, and additional characters were gathered from plastid (rpL16) and nuclear (ITS) DNA data of the unusual individuals in addition to E. corollata, E. pubentissima, and all other commonly recognized species of Euphorbia sect. Tithymalopsis occurring in eastern North America. The PCA indicates that the individuals are usually morphologically distinct, and DNA data indicate that they often have unique sequences different from E. corollata or E. pubentissima. These data support our hypothesis that the unusual plants represent an overlooked species, which was previously named Euphorbia apocynifolia Small. In addition, our phylogenetic analyses of DNA data are not fully congruent with recent hypotheses of intra-sectional relationships based on morphology.

Survey of the Vascular Flora of Thompson Creek, Chesterfield County, South Carolina

Charles N. Horn
Bailey Gause
2026-07-29

The Carolina Wildlands Foundation is working to encourage future naturalists to better understand the botany and ecology of Thompson Creek in Chesterfield County, South Carolina. The creek flows through the piedmont physiographic province and over the Carolina Slate Belt. This survey of about 5 km of floodplain resulted in the documentation of 272 species of vascular plants. Most species (65.8%) have a widespread distribution in South Carolina. A relatively high 17.3% of the flora is non- native. Two invasive species, Ligustrum sinense and Microstegium vimineum, are of concern given their ability to alter the ecology of the floodplain. Eurybia mirabilis is unusual on the creek and is of conservation concern. This survey will provide a baseline for future research in the watershed.

Effects of Nitrogen Enrichment on Early-Stage Wood Decomposition in a Southern Appalachian Forest

Rylee Strassner
E. Ashley Adams
2026-07-29

Nitrogen (N) availability is shifting across forest ecosystems due to spatial variation in atmospheric N deposition and changing biogeochemical dynamics under global change. These shifts in N supply have implications for woody debris decomposition, a key process regulating carbon (C) turnover and storage in forests. Because wood is typically low in N, changes in external N availability can alter microbial activity and decomposition pathways, influencing both the rate and fate of C during decay. This study investigates how low-level N enrichment (5 kg N ha^–1 yr^–1) affects the wood decomposition of two common tree species, Liriodendron tulipifera and Pinus strobus, in Southern Appalachian forests over a one-year period. We hypothesized that L. tulipifera would experience greater mass loss than P. strobus due to faster decomposition, and that N enrichment would accelerate decomposition of both species. Species Liriodendron tulipifera and P. strobus differed in wood chemical composition, particularly in lignin and cellulose content. In contrast, N enrichment had a minimal impact on decomposition dynamics. These results suggest that species is the dominant driver of early-stage wood decomposition. Given the short duration of this study and low rate of N enrichment, further research is needed to determine how these dynamics unfold over time and at what threshold N enrichment alters decomposition trajectories. As global changes reshape forest composition and nutrient patterns, understanding the combined influence of wood chemistry and nutrient availability will be essential for accurately predicting C storage in forest ecosystems.

A Synthesis of Ruppia maritima (Wigeongrass) Seed Ecology with Implications for Seed-based Seagrass Restoration

Megan E. Gannon
Hyun Jung Cho, Anna B. Ponce, and Khanyisille N. Tshabalala
2026-07-24

Seagrasses are declining globally, increasing interest in scalable seed-based restoration. Ruppia maritima (wigeongrass) is a pioneer submerged aquatic plant species that occupies variable-salinity estuaries and often expands following disturbance. This review synthesizes published literature describing relevant field and laboratory observations and research to evaluate seed production, seed- bank dynamics, storage, viability, germination, and early recruitment in R. maritima. Studies were drawn primarily from eastern United States estuaries, with some comparisons from South America, Australia, and Asia. Ruppia maritima in the eastern United States, like other global Ruppia species, produces abundant but episodic seeds, but its seed-bank longevity, viability, and recruitment vary with habitat stability and local hydrologic regime. Germination is commonly inhibited by elevated salinity while viability is retained, and often increases, after salinity reduction, indicating osmotic control and salinity-history effects. Temperature and drying further regulate germination in population- and habitat-specific ways. For restoration, seed collection, storage, and deployment should be matched to local salinity, temperature, and hydrologic conditions, while protecting donor/source beds and recognizing that short-lived seed banks and seedling establishment may constrain recruitment.

Noteworthy Collections: First Documentation of Patrin’s Violet, Viola patrinii (Violaceae) in the Southeastern United States

Jonathon P. Osborne
2026-07-24

The collection and identification of this population of Viola patrinii DC. ex Ging. in New Orleans, Louisiana, marks the first confirmed observation of this species in the southeastern United States. Though V. patrinii inhabits a cooler and more northerly native range in eastern Russia, Mongolia, China, the Korean Peninsula, and Japan (Chen et al. 2007), a study by Lee and Hwang (2006) showed that among eight species of east Asian Viola species, V. patrinii maintained some of the highest germination rates (65.8%) at warmer temperatures (20–25°C) and a germination rate of 17.3–25.3% with no dormancy period at all. Given these high germination rates as well as the persistence of this population since its introduction in New Orleans, the potential for these V. patrinii to spread outside of the city is possible but has yet to be tested under local conditions.