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Full-Text Articles in Life Sciences
Morphological, Genetic, And Environmental Characterization Of An Unusual Population Of Isoetes (Isoetaceae, Lycopodiophyta), Shannon L. Walker
Morphological, Genetic, And Environmental Characterization Of An Unusual Population Of Isoetes (Isoetaceae, Lycopodiophyta), Shannon L. Walker
Honors Theses
A large and unusual population of Isoetes (Isoetaceae, Lycopodiophyta) in the DeSoto National Forest, Wayne County, Mississippi, was studied to determine if the individuals there represent a new species or if they represent part of the variation of the one primary species of the longleaf pine belt of Mississippi, Isoetes louisianensis, which it most closely resembles. The unusual population and specimens of known Isoetes louisianensis were examined comparatively based on morphology, megaspore ornamentation, examination of habitat characteristics, and phylogenetic analysis of DNA sequence data from the nuclear internal transcribed spacer 1 and 2 (ITS) and the 5.8S ribosomal gene. No …
Species Delimitation And Phylogenetic Relationships Of The Wild Yams (Dioscorea) Native To Eastern North America, Tori A. Collins
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 …
A New Species Of Euphorbia Subgenus Chamaesyce Section Alectoroctonum (Euphorbiaceae) From Limestone Hills Of Wayne County, Mississippi, Andrew C. Fennell
A New Species Of Euphorbia Subgenus Chamaesyce Section Alectoroctonum (Euphorbiaceae) From Limestone Hills Of Wayne County, Mississippi, Andrew C. Fennell
Honors Theses
As part of a project to document the vascular flora of Wayne County, Mississippi, an unusual Euphorbia, which keys to the Euphorbia corollata complex, was encountered in mature hardwood forests in limestone regions. Unlike typical E. corollata and E. pubentissima, these individuals have long petioles (0.4–1.2 cm), oval to ovate leaves, short stature, small cyathia, small seeds, and a different phenology. In order to test species boundaries, morphological character differences were explored using principal component analysis (PCA), and additional characters were gathered from plastid (rpL16) and nuclear (ITS) DNA data of the unusual individuals as well …