Castanea

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Current Issue (87-1)

Notes on the Prairie Nymph, Herbertia lahue ssp. caerulea, (Iridaceae) at Vicksburg Military National Military Park, Mississippi

July 5, 2022

The prairie nymph, Herbertia lahue ssp. caerula, is a critically imperiled grassland plant in Mississippi. A large population of the prairie nymph occurs at the Vicksburg National Military Park. This population of prairie nymph occurs in a managed anthropogenic grassland with a host of associated native and exotic species. With the assistance of National Park Service staff an experiment investigating the effects of their mowing and a study of the growing conditions and pollinators of the plant was initiated. The mowing experiment was abandoned after two years because of the COVID-19 pandemic and yielded no significant results. Here we report on the growing conditions and associated species. The syrphid fly, Toxomerus marginatus, was observed to be a frequent flower visitor.

The Persistence of State-Listed Endangered and Threatened Seed Plants in Populated Illinois Landscapes

July 11, 2022

The state of Illinois has few natural areas remaining due to anthropogenic changes caused by agriculture, industry, and urbanization. This study investigates the seed plants at the greatest risk of extirpation from Illinois, the state-listed endangered and threatened species, and their occurrence relative to land use. The Illinois Endangered Species Protection Board and the Illinois Natural History Survey chronicle the occurrence and distribution of state-listed endangered and threatened species. We extracted the number of endangered/threatened species per county from these records. We also calculated the proportion of land cover per county for anthropogenic, non-anthropogenic, and protected areas. Using these data, we modeled the distribution of state-listed endangered and threatened seed plants as a function of land cover and human population density. Our study revealed that many endangered plant species are persisting in counties with high levels of human population density. A high degree of agricultural land cover was negatively associated with the presence of endangered/threatened seed plant species. We provide statistical evidence that endangered/threatened species are persistent in highly populated areas, given that there are protected lands with adequate habitat for them to grow. These results underscore the importance of protecting natural habitats. Urban development has preserved some of these habitats by establishing protected lands that allow the continued existence of many species. The role that protected lands play in the conservation of biodiversity is crucial to prevent extirpation of endangered/threatened seed plant species in Illinois.

Noteworthy Collections—South Carolina

July 15, 2022

Discussion is provided for an occurrence of Macbridea caroliniana thought to be extirpated (Berkeley County) and five new occurrences collected 2019–2020 on the South Carolina Coastal Plain. One new occurrence is a county record (Charleston County). Four new occurrences along the Black River through Berkeley and Williamsburg counties suggest favorable habitat in that region. Findings suggest that this species may be underreported in South Carolina and effort should be placed in identifying disturbed habitat in conserved natural areas that may harbor this rare plant.

The Vascular Flora of Autauga County, Alabama

August 3, 2022

The vascular flora of Autauga County, Alabama, was surveyed from 2016 to 2020. A total of 168 families, 617 genera, 1,393 species, and eight named hybrids are reported. Of the 1,393 species, 1,097 were collected during this study and 296 are from the search of online databases. Thirty of the species are listed on The Inventory List of Rare, Threatened, and Endangered Plants and Animals of Alabama. Approximately 21.4% of the flora (298 species), are considered non-native. Families with the largest number of species and named hybrids were Asteraceae (162), Poaceae (147), Fabaceae (100), Cyperaceae (96), Rosaceae (42), and Lamiaceae (33).

Distinguishing Saplings of Pines of Piedmont Upland Grassland Systems

August 31, 2022

The development and assessment of Piedmont upland grassland restoration efforts is hampered in part by continued challenges in identifying immature individuals of three associated pines, Pinus echinata, P. taeda, and P. virginiana, the penultimate of which is thought alien to the system. To help fill this gap, we studied three quantitative and 25 qualitative characters in 174, 2- to 5-year-old saplings in managed stands in Durham County (North Carolina) and 169 herbarium specimens of mature individuals from 94 Piedmont counties from Georgia to Virginia. Although mean short-shoot needle and fascicle sheath lengths differed significantly between lifestage classes of the three species (F8,335=185, p<0.0001 and F8,335=173.5, p<0.0001, respectively), there was substantial range overlap, likely contributing to diagnostic confusion in the field when existing keys are applied. For example, needle length ranges of all lifestage classes of all species overlapped with those of mature P. echinata and 2-year-old P. virginiana. In addition, at the apex of the previous season’s growth, 2-year-old saplings of P. echinata and P. virginiana exhibited needles either predominantly or in higher percentages of threes, than the contrasting described preponderance of pairs for mature individuals. Of the 25 qualitative characters evaluated, we found (1) absence of decurrency glaucescence distinguishes 2- to 5-year-old saplings of P. taeda from P. echinata and P. virginiana, and (2) absence of stomatal plugs distinguishes P. virginiana from the others. A diagnostic key to saplings is provided.