Examining Cypripedium (Orchidaceae)Hybridization in a Prairie/Woodland Ecotone
Hybridization has been shown to be an important process in plant speciation. Ascertaining the lineage of suspected hybrid individuals can be complicated when using morphological characters alone. This study examined morphological characters as well as nuclear-ribosomal internal transcribed spacers of Cypripedium candidum, C. parviflorum var. pubescens and C. x favillianum in order to test the hypothesis that suspected hybrid individuals growing along a prairie/woodland ecotone in Resthaven Wildlife Area, Castalia, Ohio indeed had hybrid ancestry. Furthermore, we examined whether C. parviflorum var. pubescens was extirpated from the site. Fifteen morphological characters were employed in a discriminant function analysis which revealed clear separation between the hybrids and the parental taxa. Additionally, analysis of the morphological data showed ten of the fifteen variables measured in the hybrids were intermediate between the parental taxa. Three ITS types were detected in the hybrid populations, two of which were identical to the parental taxa and a third which was identical to C. parviflorum var. pubescens with the exception of a single nucleotide substitution. The results support the hypothesis that the suspected hybrid individuals were indeed hybrids, and C. parviflorum var. pubescens is extirpated from the Resthaven site.
School:Bowling Green State University
School Location:USA - Ohio
Source Type:Master's Thesis
Keywords:cypripedium orchid its taxonomy hybridization lady s slipper
Date of Publication:01/01/2008