BRICKER1, JERALD S.* AND GREGORY K. BROWN2. 1Division of Math, Agriculture, Science, and Health, Laramie County Community College, 1400 E. College Drive, Cheyenne, WY 82007, 2Department of Botany, University of Wyoming, Laramie, WY 82071. - A molecular phylogeny for Oönopsis (Asteraceae).
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Oönopsis (E. L. Greene, 1896) is a genus of herbaceous,
selenium accumulating perennials, nearly endemic to the high plains
of central and eastern Wyoming and eastern Colorado. For much of
it's taxonomic history Oönopsis has been recognized as a
subgenus within Haplopappus (sensu Hall, 1928). Recent
molecular evidence corroborates morphological reinterpretation to
support recognition of Oönopsis as a monophyletic genus.
The six taxa currently recognized within Oönopsis have
been the focus of recent field, morphological, chromosomal, flavonoid,
and cladistic studies. The objective of this study was to generate
phylogenetic hypotheses using DNA sequence from the internal
transcribed spacer regions one and two (ITS-1 and ITS-2) of nuclear
ribosomal DNA from exemplars representing all taxa within
Oönopsis , and to use these molecular hypotheses to test
the cladistic hypotheses generated from traditional data. Outgroup
DNA sequence was obtained from Machaeranthera
tanacetifolia . In general, the hypothesis generated from
ITS-1 & 2 DNA sequence data supports the morphologically-based
phylogenetic hypothesis. The conflict between hypotheses involves
the placement of O. foliosa var.
monocephala . The molecular phylogeny places var.
monocephala in a well supported clade with O.
multicaulis , and not with O. foliosa var.
foliosa , as is suggested by morphological data.