In Memoriam: Edward Clebsch and Joseph Winstead
Edward Clebsch and Joseph Winstead
Volume 85 - Issue 1 (May 2020)
Floral Biology of Mitreola petiolata and M. sessilifolia (Loganiaceae): Chasmogamous Flowers with Massive Post-Anthesis Precocious Pollen Germination
Mitreola petiolata and M. sessilifolia in the Loganiaceae are similar wetland annuals occurring in tropical, subtropical, and temperate regions in the southeastern U.S., Africa, Asia, and Oceania. The flowers of both species have previously been described to open briefly with an apparent window for outside pollination, followed by flower closure and massive pollen germination within the anthers with pollen tubes covering the adjacent stigma. The phenomenon was documented with field observations, floral dissections, and light and scanning electron microscopy. Both species open their flowers for a brief 6–8 hour window. Subsequently, pollen germinates within the closed or closing flower with pollen tubes completely covering the stigma. The prevalence and importance of selfing by precocious pollen germination are discussed.
2020 Richard and Minnie Windler Award Recipients
The Richard and Minnie Windler Award recognizes the authors of the best systematics and ecology papers published in Castanea during the previous year. For 2020, authors of two articles were selected as winners: Max Lanning and Kathy Mathews for “Taxonomy, Distribution, and Lectotypification of Two Rare, Southern Appalachian Saxifrages, Micranthes careyana and M. caroliniana” (Castanea 84[1]:93–108); and Ryan Huish, Amy E. Faivre, Melissa Manow, and Conley K. McMullen for “Investigations Into the Reproductive Biology of the Southern Appalachian Endemic Piratebush (Buckleya distichophylla): Pollination Biology, Fruit Development, and Seed Germination” (Castanea 84[1]:3–27).
Book Review — Mushrooms of the Georgia Piedmont and Southern Appalachians
Mary L. Woehrel and William H. Light. Mushrooms of the Georgia Piedmont and Southern Appalachians. 2017. 644 p. 1140 color photos, 41 diagrams, 4 tables, 1 map. University of Georgia Press, Athens, Georgia. $59.95. ISBN 978-0-8203-5003-5
Survey of Rare Plants Within a Calcareous Flatwoods Community and Analysis of Plant-Environmental Relationships
OPEN ACCESS – No subscription required to view/download full article PDF ABSTRACT: The Southern Ridge and Valley Calcareous Flatwoods community is represented by a diverse and unique plant association. Atypical edaphic processes may explain the presence of disjunct or nearly endemic species, including several federal/state endangered and rare species. To evaluate this community, we surveyed a 238-ha plot at Berry College (Floyd County, GA) within a known calcareous flatwoods habitat. Contiguous 30 m wide transects were surveyed for 12 focal species in 2018. Canopy photos and soil samples were taken at sites where focal plants were found, as well as at 30 random sites within the plot. Soils were analyzed for pH, lime buffer capacity (LBC), Ca, Mg, P, K, Mn, and Zn. Canopy photos were analyzed for variables related to canopy openness. Of focal species, only Asclepias hirtella (N=52) and Marshallia mohrii (N=12) were found during the survey. Contrary
Annual Signature in the Taproots of Echinacea laevigata and E. pallida (Asteraceae, Heliantheae)
The annual signature of the roots of relatively few species of North American herbaceous perennials is known, which is unfortunate, considering the potential contributions an increased understanding of age structure of populations of such species could represent. To help fill this gap, we briefly communicate here results of recent work on Echinacea laevigata and E. pallida (Asteraceae, Heliantheae), both species of conservation concern in the eastern United States. Analysis of cross-sections of individuals of known age of both species revealed an annual signature consistent with that reported for other herbaceous perennials, namely the development of clusters of vessels with conspicuously large diameters, marking annual spring root growth, followed by vessels of reduced diameter in the remainder of the year.
Plant Community Composition in Two Human-Modified Landscapes, a Powerline Corridor and an Old Field
ABSTRACT: Human landscape modification elicits changes in plant community composition due to altered microclimate conditions. We asked the question whether floristic composition, abundance, species richness, and diversity differ between habitat types in two human-modified landscapes, with contrasting management regimes. We measured species richness and cover of all vascular plants in forest, edge, and corridor habitats of a powerline easement, as well as in a nearby old field. Powerline corridor habitat had 21% more species than adjoining forest habitat and was dominated by shrub and herbaceous species. We also found that soil pH and litter depth are significant predictors of species richness along powerline corridor edges and in open old-field habitat. Particularly, we observed maximum species richness in plots with moderately high soil pH of between 5 and 5.5 along powerline corridor edges and in open old-field habitat. Powerline corridor plots with less surface litter also had higher species richness. Invasive
The Vascular Flora of Chewacla State Park, Lee County, Alabama
Initially formed as a Civilian Conservation Corps camp in 1935, Chewacla State Park is a 282 ha property established in 1939. The park is currently managed by the Alabama Department of Conservation and Natural Resources, State Parks Division as a public recreational resource. A floral survey of this area was conducted from August 2014 through May 2019. A total of 704 species (incl. five hybrids) from 415 genera and 137 families were collected in the park. Asteraceae was the largest family with 98 species. Poaceae, Fabaceae, and Cyperaceae were the next largest families with 72, 48, and 48 species, respectively. Carex (Cyperaceae) was the largest genus, represented by 25 species. Seventy species are reported for the first time from Lee County, and one for the state of Alabama. One hundred and thirty-nine (19.7%) non-native species were collected during the surveys. Voucher plant collections made for this study are held at
Acorn Weevil (Coleoptera: Curculionidae) Predation Dynamics in a Mississippi Bottomland Hardwood Forest
Curculio and Conotrachelus weevils (Coleoptera: Curculionidae) can render the majority of North American Quercus spp. acorn crops nonviable, thereby reducing food resources for wildlife and limiting opportunities for seedling establishment. Acorn predation by weevils at the individual tree level can be influenced by many factors, and research specifically investigating acorn predation by weevils in seasonally flooded bottomland oak forests is lacking. We placed cone emergence traps in a periodically flooded forest on the Sam D. Hamilton Noxubee National Wildlife Refuge near Brooksville, Mississippi to obtain weevil population parameter estimates, record emergence phenologies, and identify variables that may aid in understanding tree-to-tree variability in acorn predation rates. Forty-three Curculio weevils representing five species emerged from mid-August through early November, and 56% of those captured emerged over an 11-day period in mid-September. Sixty-four Conotrachelus weevils representing two species emerged from mid-August through late November and occurred at nearly twice the density of
Scientific Note: Insects associated with Guettarda scabra in Everglades National Park, Florida
Guettarda scabra leaves are consumed by a variety of moth caterpillars, some with adults that visit the flowers and may serve as pollinators. Flower-opening is hastened by eager flower-flies, and during the night the flowers are visited by hawk moths (Sphingidae); in the morning they are visited by butterflies.