Genetic Variation in the Extreme Endemic Pedicularis furbishiae , (Scrophulariaceae)

Endemic species are commonly hypothesized to have little genetic variation because of inbreeding, genetic, bottlenecks, and/or other factors. We investigated genetic variation in, Pedicularis furbishiae(Scrophulariaceae), an endangered endemic of the St. John River valley in northern Maine, by examining electrophoretic patterns at 22 loci in 28 individuals distributed among four populations. No variation appeared at any of the loci, although this sample was sufficient to detect any variant alleles with a frequency of 5.2 percent or more with 95 percent probability. This lack of variation is probably due to founder effects accompanying the original postglacial establishment and subsequent repeated episodes of population establishment and local extinction along the St. John.