Systematics/Phytogeography / Taxonomie/ Section
Park, Michael S. , Baldwin, Bruce G. , Armbruster, W. Scott .
Did Collinsia metamorphica ined. (Plantaginaceae) descend from a peripheral isolate of the widespread C. childii?
Collinsia metamorphica ined. is a newly discovered species known only from seven populations on scree and talus derived from metamorphosed Devonian sedimentary rock in the upper watershed of the Merced River in the Sierra Nevada, California. This area of the Yosemite region is known for high floristic endemism. Harlan Lewis first proposed that a narrow endemic found in this same area, Clarkia lingulata, diverged rapidly from a peripheral isolate of Clarkia biloba (Onagraceae). Collinsia metamorphica was previously thought to be a disjunct population of Collinsia linearis, known in California only from the Klamath Region. However, morphological comparisons with Collinsia linearis indicated that the Sierran populations were distinct and the initial nrDNA tree showed them to be most closely related to Collinsia childii, which is distantly related to Collinsia linearis. Geographic distributions of the narrowly endemic Collinsia metamorphica and widespread Collinsia childii (on granites in the Sierra Nevada and Transverse, South Coast, and Peninsular ranges of California) suggested a similar pattern of peripheral isolation to that proposed for Clarkia lingulata from Clarkia biloba. Subsequent analyses of nrDNA and cpDNA sequences representing populations throughout the geographic distributions of Collinsia metamorphica and Collinsia childii resolved the two species as reciprocally monophyletic. Fieldwork uncovered striking variation between populations of Collinsia metamorphica -- differences in corolla shape and color that correlate with climatic differences. The two morphological varieties of C. metamorphica are distinct in both nrDNA and cpDNA trees. Collinsia metamorphica appears to be a more ancient lineage than originally suspected, rather than a recent peripheral isolate of Collinsia childii.
Log in to add this item to your schedule
1 - University of California, Berkeley, Department of Integrative Biology, University and Jepson Herbaria, 1001 Valley Life Sciences Bldg. #2465, Berkeley, California, 94720, USA
2 - University of Portsmouth, School of Biological Sciences, King Henry Building, Portsmouth, PO1 2DY, UK
Presentation Type: Oral Paper:Papers for Sections
Location: Room 5/Woodward
Date: Tuesday, July 29th, 2008
Time: 1:00 PM