An investigation of potential additional species and hybridization in early saxifrage (Micranthes virginiensis)
- WCU Author/Contributor (non-WCU co-authors, if there are any, appear on document)
- Tara Kathleen Hall (Creator)
- Institution
- Western Carolina University (WCU )
- Web Site: http://library.wcu.edu/
- Advisor
- Katherine Mathews
Abstract: Micranthes virginiensis (Saxifragaceae) is an herbaceous, flowering plant native to Eastern North America with a range extending from Arkansas into Maine and Canada. This broad range, known from previous studies to contain individuals with varying chromosome numbers and morphological variation outside of the current formal description, indicates the need for a reexamination of the taxonomy of this species. Some populations in Southeastern Appalachia display intermediate traits between M. virginiensis and M. careyana and have unresolved phylogenetic placement, raising the possibility of hybridization. This study aimed to define the identity of M. virginiensis by comprehensively sampling populations from throughout this species’ range. Specifically, this study will explore hypotheses of hybridization and cryptic or undescribed species within M. virginiensis based on morphometric and chromosome data collected from voucher specimens across Eastern North America. Floral, fruit, and leaf measurements were analyzed to investigate morphological variation across the species’ range. Chromosome counts from M. careyana, M. palmeri, and M. petiolaris populations all showed diploidy (2n = 20), representing the first known chromosome counts for these species. Tetraploidy and unique floral morphology in the Gap Creek and Wadakoe Mountain escarpment populations, where the distribution of M. virginiensis and M. careyana overlap, indicate a new species of hybrid origin which could be described in a future publication. Other tetraploid populations in the Southeast have no known morphological differences from diploid M. virginiensis, suggesting autopolyploidy. Additionally, the diploid Polk Co., NC escarpment populations exhibit unique floral morphology with spreading and somewhat reflexed petals and may represent a separate lineage.
An investigation of potential additional species and hybridization in early saxifrage (Micranthes virginiensis)
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Created on 7/1/2023
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Additional Information
- Publication
- Thesis
- Language: English
- Date: 2023
- Subjects
- Saxifraga
- Wild flowers
- Saxifragaceae
- Plant hybridization
- Flowers—Morphology