Phylogeography of the Narrow Endemic, Helenium virginicum (Asteraceae), Based upon ITS Sequence Comparisons
The federally listed threatened species, Helenium virginicum, is endemic to 30 sinkhole ponds in two counties in Virginia, but a Helenium population in Pomona, Missouri, differs scarcely from H. virginicum from Virginia in morphology, ecology, and non-coding nrDNA ITS sequences. In response to continuing taxonomic uncertainty regarding the Missouri population, we enlarged our ITS comparisons from our previous work to include 48 populations, more than doubling the number of H. virginicum populations, and including populations of H. autumnale and H. flexuosum from 12 states in the United States and two Canadian provinces. Phylogenetic analyses were conducted using Bayesian, maximum-likelihood, and maximum-parsimony methods, and showed strong support for a monophyletic species of all H. virginicum from Virginia, the Pomona population and 29 other recently discovered populations in Missouri. We conclude that H. virginicum is narrowly endemic and disjunct between Virginia and Missouri. Additionally, one population of H. autumnale from the Bruce Peninsula, Canada, was found to be the sister group to H. virginicum. We discuss the impact of Pleistocene and Holocene geoclimatic changes on the phylogeography of these plants, including the possibility that the H. autumnale complex has become more disjunct and narrowly endemic since the Xerothermic Period (8–4Ka).
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
Document Type: Regular Paper
Publication date: 2005-10-01
More about this publication?
- Systematic Botany is the scientific journal of the American Society of Plant Taxonomists and publishes four issues per year.
2011 Impact Factor: 1.517
2011 ISI Journal Citation Reports® Rankings: 87/190 - Plant Sciences
34/45 - Evolutionary Biology
- Editorial Board
- Information for Authors
- Submit a Paper
- Subscribe to this Title
- Membership Information
- Ingenta Connect is not responsible for the content or availability of external websites