Systematics Section / ASPT
Gillespie, Emily L. , Reece, L. Court , Murrell, Zack E. .
Re-evaluation of Species Boundaries in the Carex eburnea Complex Using Morphometric, Molecular and Biogeographical Data.
The Carex eburnea complex (Carex Section Albae) is comprised of two named species, C. eburnea Boott and C. mckittrickensis Ball. Carex eburnea is widely distributed on limestone in North America and C. mckittrickensis exists as a single population in the Guadalupe Mountains of Texas. The objectives of this study were to 1) describe the phylogeography of Carex eburnea using Inter-Simple Sequence Repeats (ISSRs) and morphometric analyses, and 2) examine species delineation and species relationships within the Carex eburnea complex. A distribution map was generated for the complex using 798 specimens from 11 herbaria and this distribution was compared with known limestone outcrops in North and Central America. Morphometric analysis was performed on 124 specimens. Univariate statistical analysis and analysis of missing data indicated that 14 of 28 measurements were useful in evaluating variation in the Section. Principal Components Analysis (PCA) of 14 raw variables and 12 ratios was used to compare variation within Section Albae and within the C. eburnea complex. Carex mckittrickensis could be easily differentiated from C. eburnea with the raw data, but was clustered with C. eburnea using the ratios, suggesting that the differences between these two taxa are more a function of size than shape. Populations were sampled for DNA analysis throughout the range of the complex. Sixty-six ISSR primers were screened, of which seven were variable and reproducible; 52 bands were included in the data set. Molecular data were used to generate distance and parsimony trees, which were evaluated using bootstrap and Bayesian analyses. Molecular, morphological and biogeographical analyses suggest that the C. mckittrickensis population is no more divergent than any other population of C. eburnea and does not merit recognition as a segregate species. The C. eburnea complex illustrates the complexity of incorporating monophyly, metaphyly and paraphyly in species recognition and delineation.
1 - Appalachian State University, Biology, 572 Rivers Street, Boone, North Carolina, 28608, USA
Presentation Type: Paper
Location: Cottonwood A (Snowbird Center)
Date: Wednesday, August 4th, 2004
Time: 4:00 PM