Integrative species delimitation: incorporating multiple types of data
Broe, Michael , Freudenstein, John .
The role of molecular evidence in delimiting groups with reduced morphology: a case-study from the monotropoids &l.
Hypopitys Hill is a mycoheterotrophic, achlorophyllous genus in the subfamily Monotropoideae (Ericaceae), with a circumboreal distribution in Eurasia and the Americas. Like other monotropoids, Hypopitys presents a challenge to phylogenetic analysis due to the high degree of convergent evolution resulting from reductive adaptations to a mycoheterotrophic habit. In addition, color-form, such a striking character on first observation, ranging from tawny-white and yellow, through salmon to dark-red, is highly variable even within individual populations. Because of this combination of morphological reduction and high variability, the taxonomy of the genus is confused. Species and sub-species have been erected and subsequently synonymized to a remarkable degree. Small (1914) recognized five species in N. America alone, while in the most recent monograph Wallace (1975) rejected all such distinctions, choosing to synonymize some 80 putative species, subspecies and varieties, noting 'there are no segregates that yet warrant taxonomic recognition'. We performed an extensive sampling of Hypopitys across N. America and Europe, and present molecular evidence for a revised treatment of this group based on rDNA and single-copy nuclear loci. The molecular data clearly distinguishes Old World and New World segregates, and provides strong support for a number of species within N. America with well-defined geographic distributions: a southern clade found in Mexico, New Mexico and Arizona; two distinct clades on the west coast, with sympatry in southern Oregon; the northmost of these clades disjunct in the Great Lakes area, with a subclade extending down into Ohio. This clade is in turn sympatric with a highly distinct south-eastern clade, extending from New York state south to North Carolina and Georgia. We take this south-eastern clade as a case study, and based on distributional, morphological, phenological and molecular evidence, argue that this clade corresponds precisely to Hypopitys lanuginosa (Michx.) Nutt., which once again warrants taxonomic recognition.
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1 - The Ohio State University, Museum Of Biological Diversity, 1315 Kinnear Rd, Columbus, OH, 43212, USA
2 - Ohio State University, MUSEUM OF BIOLOGICAL DIVERSITY, 1315 KINNEAR RD, COLUMBUS, OH, 43212-1157, USA
Presentation Type: Symposium or Colloquium Presentation
Location: Delaware C/Hyatt
Date: Monday, July 9th, 2012
Time: 11:00 AM