Abstract Detail

Systematics Section

Kephart, Susan [1], Clark-Snustad, Kindra [2], Sultany, Molly [1], Digby, Anna [3], Adler, Constance [4].

Phenotypic differentiation and reproductive isolation in sympatric species of Camassia (Agavaceae): Are species congruent based on multiple criteria?

Phenotypic and niche differentiation, reproductive cohesion, and phylogenetic independence are the hallmarks our most prevalent species concepts and underlie the effective delimitation of taxa whose populations are both temporally and spatially dynamic. Today, genetic evidence informs taxonomic delimitation whereas species identification relies largely on trait variation, yet we still lack comprehensive data on the extent to which morphology, reproductive isolation, and ecological similarity vary in tandem or opposition for multiple populations of related, but divergent species. Thus, we investigated whether sympatric species of Camassia (Agavaceae), exhibit levels of ecological similarity and genetic isolation congruent with the degree of phenetic similarity at multiple sites spanning a broad geographic range in western North America. We measured ecological (e.g., light, temperature), morphological, and phenological variation, as well as post-mating barriers to hybrid formation, for species pairs that included sympatric C. quamash and C. leichtlinii from northwestern Oregon to northeastern California. These species represent distinct phylogenetic lineages for which subspecific differentiation has been especially problematic, particularly in C. quamash. Analyses thus far demonstrate asymmetric barriers to hybridization and suggest that morphological complexity is greatest in sympatric sites where crossability and ecological overlap are high. Camassia is an important spring wildflower visited by generalist pollinators in wetland prairies and oak savannahs. Detailed characterization of morphological and ecological differences will help improve taxonomic keys while assessments of reproductive independence and pollinator overlap will lend insight into the patterns of variability and hybridity that often confound species identification.

Broader Impacts:
Student mentoring and training,development of taxonomic keys

1 - Willamette University, Biology, 900 State Street, Salem, OR, 97301, USA
2 - University of Washington, Seattle, WA, 98195, USA
3 - Willamette University, Biology, Salem, OR, 97301, USA
4 - 980 Parma Way, Los Altos, CA, 94024, USA

Keywords:
Agavaceae
Camassia
hybridization
Morphometrics
reproductive isolation
species concept
pollination.

Presentation Type: Poster:Posters for Sections
Session: P
Location: Hall A/Convention Center
Date: Monday, August 2nd, 2010
Time: 5:30 PM
Number: PSY041
Abstract ID:781