Life Sciences Commons^™

Reassessment Of Species Boundaries And Phylogenetic Relationships In The Desmodium Ciliare Complex (Fabaceae) Using Morphological And Dna Data, Joshua Wilkinson

Master's Theses

Desmodium (Beggar's ticks) is a generally weedy genus of approximately 280 species in the angiosperm family Fabaceae (Subfamily Papilionoideae, Tribe Desmodieae) characterized by indehiscent loments constricted into segments. Within the Southeastern U.S., the Desmodium ciliare group is one of two Desmodium species complexes that have been historically difficult, with much argument about the limits of species and the role of hybridization. There are three commonly recognized species within the D. ciliare group, D. ciliare (Muhl. ex Willd.) DC., Desmodium marilandicum (L.) DC., and D. obtusum (Muhl. ex Willd.) DC., with two supposed hybrids in addition to the …

A Comparison Of Natural, Living, And Hardened Shorelines Ability To Prevent Coastal Erosion And Maintain A Healthy Ecosystem, Gabrielle Spellmann

Master's Theses

It is important to find a suitable method to protect the U.S. Gulf Coast shoreline, since its’ low elevation and the Loop current make it vulnerable to sea level rise. I focused on two manmade methods, hardened, and living shorelines, of coastal protection for when the natural marsh suffers excess erosion rates. Living shorelines are a suite of shoreline conservation and restoration techniques that usually involve some sort of hardened structure that dampens wave energy so that the native vegetation behind it can take root and stabilize the shoreline. This study looked at six different sites, all containing a natural, …

Vegetative Community And Health Assessment Of A Constructed Juncus-Dominated Salt Marsh In The Northern Gulf Of Mexico, Nickolas R. Murphy

Master's Theses

Deer Island is a coastal habitat which provides a buffer from storm and flood damage as well as shore-line stabilization to the mainland of Biloxi, Mississippi. A third of the land has been lost since 1850, largely driven by tropical storm and hurricane impacts as well as sea level rise. The United States Army Corps of Engineers and Mississippi Department of Marine Resources have targeted the shores of the island as sites for restoration using beneficial use dredged material, and two sites of differing age have since been planted with Spartina alterniflora, Juncus roemerianus, Uniola paniculata, S. patens, and Panicum …

Leaf-Tip Morphology Does Not Support Species Status For The Seagrass Halodule Beaudettei In Florida, Usa, Michael E. Wheeler, Bradley T. Furman, Margaret O. Hall

Gulf and Caribbean Research

No abstract provided.

Effects Of Water Table Depth And Edaphic Characteristics On Plant Diversity In A Southern Mississippi Pitcher Plant Bog, Patrick Kirby

Master's Theses

This study examined the effects that water table depth and soil characteristics have on plant species richness and species composition within pitcher plant bogs across seasons. Eight piezometers were installed at random distances to monitor long-term water table depth and pressure fluctuations along a ~710-meter line transect traversing upland and bog habitats. Vegetation sampling quadrats (n=128) were set up near each piezometer. Cover data and water table depths were collected in spring and late summer. Soil samples collected from each treatment group were used to obtain soil texture and nutrient data. The summer collection period yielded a total gdiversity of …

Checklist Of The Vascular Flora, Restoration Plans, And Educational Interpretive Signs For A Remnant Prairie At The Lakewood Memorial Cemetery, Hinds County, Mississippi, Olivia Shelton

Honors Theses

A floristic survey was conducted on the eastern margin of the Lakewood Memorial Park Cemetery, located between Jackson and Clinton, Mississippi, near the western edge of the Jackson Prairie ecoregion. From soil map data and preliminary observations of the landform and flora, the eastern part of the cemetery was hypothesized to be remnant prairie now mostly covered by exotic grasses (pasture) and woodland. Plant specimens were collected, identified, and preserved in the herbarium of The University of Southern Mississippi (USMS). The survey yielded 119 species of vascular plants, of which 98 (82%) were native and 21 (18%) were non-native. Indicative …

Leaf Herbivory Induces Resistance Against Florivores In Raphanus Sativus, Andrew C. Mccall, Samantha Case, Kelsy Espy, Grant Adams, Stephen J. Murphy

Student Publications

Florivory can have significant negative effects on plant fitness, driving selection for resistance traits in flowers. In particular, herbivory to leaves may induce resistance in flowers because herbivores on leaves often become florivores on flowers as plant ontogeny proceeds. The literature on inducible resistance in floral tissues is limited, so we used a series of experiments to determine whether prior leaf damage by Spodoptera exigua (Hübner) caterpillars affected florivore preference and performance on wild radish (Raphanus sativus L.). We found that Spodoptera exigua larvae preferred petals from control plants versus petals from plants exposed to prior leaf damage, and …

Historical Change Of Seagrasses In The Mississippi And Chandeleur Sounds, Linh Thuy Pham

Dissertations

Seagrasses are important coastal resources facing numerous stressors, and losses have been documented from local to global assessments. Under the broad theme of habitat loss and fragmentation, a study of historical change in total area and landscape configuration of seagrasses in the Mississippi and Chandeleur Sounds was conducted. Mapping data was collated from a multitude of previous projects from 1940 to 2011.

Comparisons of seagrass area among various studies that used different mapping methods can result in overestimation of area change and misleading conclusions of change over time. The vegetated seagrass area (VSA) data were generalized to a common resolution …

Phylogenetic Relationships Of The Genera Of Achariaceae Based On Analyses Of Morphological And Dna Data, Corey L. Pagart

Honors Theses

Achariaceae are a mostly tropical family of flowering plants consisting of about 29 genera and 150 species of trees and shrubs. Although they are closely related to passionflowers (Passifloraceae), violets (Violaceae), and willows and cottonwoods (Salicaceae), phylogenetic relationships of the genera remain unclear because the only studies have been focused on particular genera or had limited sampling. Few studies of the family in general have been conducted, except for some on species that produce chaulmoogra oil, a commonly used historical treatment for leprosy. For my study, I investigated the relationships of the genera within the family using morphological and molecular …

Phylogenetic Relationships Of Salicaceae Based On Analyses Of Nuclear Dna Data, John Marshall Diffey

Honors Theses

Salicaceae are an economically and ecologically important family of flowering plants. The family includes willows and cottonwoods and was recently enlarged to include a large number of tropical species formerly placed in the family Flacourtiaceae. Relationships of these tropical relatives to willows and cottonwoods have been explored at a basic level using morphology and plastid DNA data, but to date no molecular phylogenies have been constructed with significant sampling of nuclear DNA, which sometimes results in a different picture of relationships because of its biparental inheritance. For this project, I sampled one region of nuclear DNA (GBSSI) across the family …

Vascular Flora Of The Possum Walk Trail At The Infinity Science Center, Hancock County, Mississippi, Hanna M. Miller

Honors Theses

The North American Coastal Plain contains some of the highest plant diversity in the temperate world. However, most of the region has remained unstudied, resulting in a lack of knowledge about the unique plant communities present there. This flora catalogues the vascular plant species along the Possum Walk Trail on the southeast corner of the Infinity Science Center in Hancock County, Mississippi. Additionally, interpretive signs have been developed to display information about engaging species and phenomena to increase public interest in native plant life and involve them conservation efforts. The site was surveyed from spring of 2015 to spring of …

The Vascular Flora Of Wayne County, Mississippi, Daniel M. Mcnair

Master's Theses

The vascular flora of Wayne County, Mississippi, was surveyed from 2013–2015, and the species of native and naturalized plants are listed. In total, 1,135 species were identified from field collections, previously collected herbarium specimens, and field observations. These belong to 556 genera and 165 families. Four of these species represent first recorded occurrences in the state of Mississippi: Blyxa aubertii Rich., Gomphrena serrata Pav. ex Moq., Isoetes valida (Engelm.) Clute, and Polypogon interruptus Kunth. GPS coordinates are given for important collection sites representing the diversity of plant communities in the county. All voucher specimens from the survey are deposited in …

Species Delimitation And Phylogenetic Relationships Of The Wild Yams (Dioscorea) Native To Eastern North America, Tori A. Collins

Honors Theses

Most taxonomic treatments currently recognize two to three species of native yams in eastern North America: Dioscorea villosa, D. floridana, and sometimes D. quaternata, a segregate of D. villosa. Earlier authors (e.g., J. K. Small) had recognized as many as five species (with D. hirticaulis and D. glauca also as segregates of D. villosa). Key morphological features in distinguishing these putative species are rhizome morphology (long and cord-like vs. thick and contorted), number of first leaves (1–3 vs. 4–7), and habitat (sandy, rocky, swampy). Unfortunately, these critical features are rarely collected and preserved on herbarium …

Phylogenetic Relationships Of Samydaceae And Taxonomic Revision Of The Species Of Casearia In South-Central Asia, Tharangamala Samarakoon

Dissertations

The flowering plant family Samydaceae was recently reinstated to include 14 genera and about 256 species of tropical trees and shrubs. Preliminary analyses of relationships in the family, however, indicated that the largest genus in the family, Casearia, is not monophyletic and that several smaller groups are probably misplaced. In order to affirm or refute those hypotheses, additional DNA sequence data with broader taxon sampling from the Old World were gathered for phylogenetic analysis. In particular, rapidly evolving plastid (matK, ndhF, psbA-trnH, trnL, and trnL-F) and nuclear (EMB2765 and GBSSI) DNA …

Osmophores, Floral Features, And Systematics Of Stanhopea (Orchidaceae), Kenneth J. Curry, Lorraine M. Mcdowell, Walter S. Judd, William Louis Stern

Faculty Publications

The floral fragrance glands (osmophores) of 18 species of Stanhopea and Sievekingia were examined through a series of developmental studies at light and electron microscope levels including late bud stages through postanthesis. Various characters were identified to be of potential systematic value and were recorded for each species. These characters included: texture of the osmophore surface, number of distinct cell layers comprising the osmophore, nature of lipid inclusions in osmophore cells, and presence or absence of plastoglobuli in osmophore amyloplasts. These characters were combined with traditional features of floral lip morphology for cladistic analysis. Sievekingia was the postulated outgroup. Stanhopea …

Initiation Of Terpenoid Synthesis In Osmophores Of Stanhopea Anfracta (Orchidaceae): A Cytochemical Study, Kenneth J. Curry

Faculty Publications

The terpenoid component of the osmophore fragrance in Stanhopea species is composed of isoprene units synthesized via the mevalonic acid pathway. Localization of hydroxymethylglutaryl CoA synthase in the pathway was achieved using a technique which elicits the formation of an electron- dense precipitate of uranyl ferrocyanide at the point where an acetyl group from acetyl CoA is transferred to acetoacetyl CoA, releasing free CoA-SH. Applying this technique to cells of the osmophore of S. anfracta resulted in a precipitate between the inner and outer mitochondrial membranes, in the smooth endoplasmic reticulum, and, to a lesser extent, on the outer surface …

Osmophores Of Stanhopea (Orchidaeceae), William Louis Stern, Kenneth J. Curry, Alec M. Pridgeon

Faculty Publications

Species of the Neotropical orchid genus Stanhopea produce a fragrance comprising terpenoids and aromatics which attracts euglossine bee pollinators. The secretory tissue, called an osmo- phore, is located in the adaxial region of a sac formed near the proximal portion of the floral lip. This region is easily recognized in Stanhopea oculata and S. wardii because it is papillate. The osmophore in these two species includes all the cells of the papillae and those directly below, that grade into fundamental tissue. Osmophore cells are more densely cytoplasmic than cells in the adjacent tissue. Numerous amyloplasts and mitochondria are seen in …

Mississippi Flora. Iv. Dicotyledon Families With Aquatic Or Wetland Species, Samuel B. Jones Jr.

Gulf and Caribbean Research

The first paper in this series treated some of the monocotyledon families with aquatic or wetland species (Jones 1974). The primary aim of this paper is to improve our knowledge of some of the dicotyledon families with aquatic and wetland plants in Mississippi. Hopefully, this paper will be reviewed and criticized by many, and corrected before the proposed Guide to the Flora of Mississippi is published.

Mississippi Flora. I. Monocotyledon Families With Aquatic Or Wetland Species, Samuel B. Jones Jr.

Gulf and Caribbean Research

Keys, distribution maps, habitats, references, nomenclature, and notes are given for some 16 families of monocotyledons occurring naturally or naturalized in Mississippi. These families all contain one or more species which are found in aquatic or wetland habitats. They are: Alismataceae, Araceae, Cannaceae, Haemodoraceae, Hydrocharitaceae, Juncaginaceae, Lemnaceae, Marantaceae, Mayacaceae, Najadaceae, Pontederiaceae, Potamogetonaceae, Rug piaceae, Sparganiaceae, Typhaceae, Zannichelliaceae.