Volume 76 - Issue 3 (Sept 2011)

2011 Elizabeth Ann Bartholomew Award Recipient — Charles N. Horn

Dr. Charles Norman Horn, Professor and Chair of the Department of Biology and Chemistry of Newberry College, Newberry, South Carolina, received the Elizabeth Ann Bartholomew Award on April 15th at the annual meeting of the Southern Appalachian Botanical Society (SABS) held in Huntsville, Alabama, in conjunction with the Association of Southeastern Biologists. This award, which honors Elisabeth Ann Bartholomew’s dedicated, untiring, and unselfish service to SABS and public and professional botanists, is presented to individuals who have distinguished themselves in professional and public service that advances our knowledge and appreciation of the world of plants and their scientific, cultural, and esthetic values, and/ or exceptional service to SABS. This year’s awardee truly meets and exceeds the standards established for the highest honor of the Society.

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Reproductive Ecology of Dirca palustris L. (Thymelaeaceae)

ABSTRACT Prevalence of sexual and asexual reproduction by plants influences genetic and spatial structure of populations. We investigated reproduction in five populations of Dirca palustris that span its distribution from Florida to North Dakota, and identified the contributions of sexual and asexual reproduction to the clustering of individuals that is characteristic of the species. In each population, maximum density of plants was documented by assessing the 10 clusters that appeared most dense. We surveyed these clusters for evidence of recent recruitment, sowed locally collected fruits to estimate potential for germination, and estimated prevalence of clones by using ISSR genetic markers. Maximum density of plants varied markedly among populations, and denser clusters showed evidence of greater recruitment over several years. Germination of seeds one year after fruits were sown varied from 7 to 56% among populations. Genetic analysis, and our observation of cotelydonary scars on young plants, indicate restricted seed dispersal

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Cinnamomum-Ardisia Forest in Northern Florida

ABSTRACT Native old-field pineland with hardwood undergrowth was replaced 42 years later by alien hardwood forest dominated by invasive species at Goodwood forest in Tallahassee, Florida. Cinnamomum camphora dominated the overstory and Ardisia crenata the undergrowth. Succession theory would have anticipated development to native southern mixed hardwood forest or a subset called magnolia-beech forest. The initial native old-field forest community, prior to alien colonization, was characterized mostly by Pinus taeda, Quercus nigra, Liquidambar styraciflua and other lowland trees that were not likely to persist indefinitely on uplands. These trees colonized abandoned fields on account of a dearth of seed sources for oak-hickory forest trees which occupied these well drained uplands in the 18th century. Oakhickory forest had been removed in the 19th century to allow the cultivation of cotton, and there was no evidence that it would recover at Goodwood forest.

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Floral Biology of an Alabama Population of the Federally Endangered Plant, Xyris tennesseensis Kral (Xyridaceae)

ABSTRACT Study of the pollination biology of endangered species can provide useful information for natural resource managers. We studied the floral biology of Xyris tennesseensis, a federally endangered species, at a site (Willett Springs) in north central Alabama. We described floral behavior and flowering phenology, supplemented pollen onto stigmas from self and outcross sources to determine its effect on seed production and germination ability, documented the floral visitor fauna, and collected data on behavior, abundance and pollen loads of floral visitor species during two years (1998–99). Flowering of the population lasted from July to September each year, but individual flowers completed blooming in about a 3-hr period beginning in late morning. On average, a single flower was visited by three insects for a total of five floral visits during its brief period of anthesis. Floral visitation was greatest when flowers first opened and declined steeply by the time flowers began

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Heterophylly of Didiplis diandra (Nutt. ex A.DC.) Wood (Lythraceae) and a Key to Some Rooted Shallow Water and Shoreline Herbs of the Mid-Atlantic Piedmont

ABSTRACT Didiplis diandra is a small shoreline aquatic plant scattered throughout eastern North America. In the Atlantic coast states from Virginia to Georgia it has been confused with other species that grow in similar habitats. Leaves of D. diandra are heterophyllous, submersed leaves average 15.4 mm long while emersed leaves average 6.3 mm long. A taxonomic key is presented to aid in identification of small shallow water and shoreline aquatic plants including members of the genera Callitriche, Crassula, Elatine and Ludwigia.

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Impacts of Nonpoint-Source Pollution on the Structure of Diatom Assemblages, Whole- Stream Oxygen Metabolism, and Growth of Selenastrum capricornutum in the Red River Watershed of North-Central Tennessee

ABSTRACT Assessments of stream biology are prerequisites to developing watershed management plans to improve ecological integrity. We sampled six streams in the Red River Watershed of North-Central Tennessee to evaluate the effects of non-point source pollution on diatom assemblages, primary production, and potential for excessive algal growth. We used diatom indices to assess the structure of diatom assemblages, changes of oxygen concentrations to evaluate primary production, and growth dynamics of the green alga Selenastrum capricornutum to evaluate the potential for excessive algal growth. The three most abundant diatom taxa collected were Nitzschia linearis (16%), Navicula reichardtiana (15%), and Navicula tripunctata (7%). Habitat impairment in all six streams is indicated by: (1) high Siltation Index values for diatom assemblages which indicate loss of biotic integrity as a result of excessive sediments from erosion, (2) high rates of whole-stream oxygen metabolism characteristic of eutrophic conditions, (3) low ratios of whole-stream gross primary

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Scientific Note: Invasion of a Southeastern Pine Savanna by Japanese Climbing Fern

Lygodium japonicum (Thunb. ex Murr.) Sw. is an invasive fern in the southeastern United States. This perennial fern, which produces twining fronds from underground rhizomes (Clarke 1936), is native to open forests and forest edges in temperate, subtropical and tropical regions of eastern and southeastern Asia, East Indies, and northern Australia (Singh and Panigrahi 1984, Munger 2005, Willis et al. 2006). Lygodium japonicum was introduced to North America as an ornamental; the first known wild populations were recorded in Georgia in 1903 (Pemberton and Ferriter 1998), but this fern is now widespread in the southeastern United States. Japanese climbing fern occurs in human-modified habitats, as well as forests and woodlands (Langeland and Burks 1998, Rosen et al. 2003), where it often forms dense mats that grow on and cover native species (Gagnon et al. 2005, Zeller and Leslie 2004). Some management plans have emphasized the dearth of scientific data on

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Survey and DNA Barcoding of Poaceae in Flat Rock Cedar Glades and Barrens State Natural Area, Murfreesboro, Tennessee

ABSTRACT A survey of grasses from the Flat Rock Cedar Glades and Barrens State Natural Area in Murfreesboro, Tennessee was undertaken during the 2008 growing season with the goal of creating a comprehensive list of grass species living in a single glade environment. Twenty four different species were identified during the survey. All had been previously recorded in Tennessee but two had not been noted in cedar glades, Sprorobilus clandestinus and Elymus hystrix, and one, Dichanthelium scoparium, had not been demonstrated in Rutherford County. The survey also provides information on species distribution within the glade, amount of sunlight exposure, and flowering time within the growing season. The plastid matK and rbcL genes and the trnH-psbA intergenic spacer region were sequenced from the specimens and are cataloged in GenBank. Variance analysis of matK and rbcL loci was conducted with the sequences produced in this study as well as GenBank archived sequences

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