Dever, Rodney , Ford-Werntz, Donna I. .
Taxonomy of the Allium cernuum complex in Appalachia.
This research investigates a botanical controversy that has gone unresolved for about a century. The Allium cernuum complex in Appalachia potentially consists of three taxa: A. cernuum Roth (nodding onion), A. allegheniense Small (Allegheny onion) and A. oxyphilum Wherry (acid-loving onion). Currently there is no consensus as to their taxonomic status, nor has this question been fully addressed. Some botanists conceive of these taxa as three distinct species whereas others recognize only A. cernuum as a species and regard the other taxa as synonyms. This study will investigate the issue by assessing variation in the morphology, anatomy, cytology and ecology of the Appalachian A. cernuum complex. A survey of specimens in ~28 eastern U.S. herbaria will be conducted to reveal the locations of disparate populations of these onions, potentially ranging from the Appalachians of Pennsylvania to Georgia. Morphological characters such as the size of leaves, scapes, pedicels, tepals and capsules will be considered in addition to shapes and colors of the perianth. Variability within and between each group will be measured using a Multivariate Statistical Analyses (Cluster and Principal Component Analysis) to evaluate relationships among these morphological characters The arrangement and number of vascular bundles can be useful diagnostically. Scape and leaf sections from various populations will be evaluated for bundle number and pattern. In order to detect chromosome variation among localities, somatic chromosomes will be examined in root tip cells. A common garden was created to determine whether the observed variation is primarily genotypic or phenotypic. Ultimately this matter is a conservation concern as A. oxyphilum and A. allegheniense are considered rare and possibly threatened in West Virginia and Virginia.
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1 - West Virginia University, Biology, Morgantown, WV , 26506, USA
2 - West Virginia University, Department of Biology, Po Box 6057, Morgantown, West Virginia, 26506-6057, USA
Presentation Type: Poster:Posters for BSA Sections
Location: Event Tent/Cliff Lodge
Date: Monday, July 27th, 2009
Time: 5:30 PM