SCHULTZ, JOANNA*, LEIGH JOHNSON, AND CAROLYN FERGUSON. Lewis-Clark State College, Division of Natural Sciences, Lewiston, ID 83501, Brigham Young University, Department of Botany and Range Science, Provo, UT 84602, Washington University, Department of Biology, St. Louis MO 63130. - Phlox idahonis (Polemoniaceae): Morphologic and molecular approaches to conservation.
Phlox idahonis Wherry (Idaho Phlox) is presently a category one
candidate for listing under the Endangered Species Act (ESA). This
ranking indicates that P. idahonis is critically imperiled due
to extreme rarity causing vulnerability to extinction. Previous
studies of P. idahonis suggest the species evolved via a
vicariant event following the Rocky Mountain orogeny, with the species
closest relatives distributed in the eastern and Midwestern United
States. However, since it's first collection and subsequent
description, the species has received little systematic attention.
Additonally, it has been suggested the species is an ornamental
Phlox introduced from the eastern United States in the
early 1900's. The taxonomic status and evolutionary relationships of
P. idahonis to other members of the genus Phlox remain
elusive. Phlox idahonis is therefore an excellent example of
a species considered for federal ranking before the taxonomic status
of the taxon has been definitively established. Our studies reveal
that P. idahonis is morphologically allied with P.
subsect. Ovatae of the eastern and Midwestern United States.
However, the species falls within the range of morphologic variability
of P. subsect. Longifoliae, comprising species of
western United States distributions. Sequencing of the internal
transcribed spacer (ITS) region of rDNA reveals that P.
idahonis is most closely related to P. subsect.
Longifoliae, notably P. longifolia. These results
support P. idahonis as an Idaho endemic and recommend federal
listing under the ESA.
Key words: Phlox idahonis, rare Idaho endemic, systematic approaches to conservation