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Clarkia xantiana (Onagraceae)

The major focus of research in my lab concerns the evolutionary ecology of reproducton, life history and geographic distribution in the California “wildflower” Clarkia xantiana. 

    Adaptation and the determinants of geographic distribution - publications

Eckhart VM, Geber MA, Morris WF, Tiffin P, Fabio ES, Moeller DA. 2011.The geography of demography: Long-term demographic studies and species distribution models reveal a species border limited by adaptation. American Naturalist, in press.

Eckhart VM, Singh I, Louthan AM, Keledjian AJ, Chu A, Moeller DM, Geber MA. 2010. Plant-soil water relations and the species border of Clarkia xantiana ssp. xantiana (Onagraceae). International Journal of Plant Sciences 171:749-760. pdf (JSTOR)

Geber MA, Eckhart VM. 2005. Experimental studies of selection and adaptation in Clarkia xantiana (Onagraceae). II. Fitness variation across a subspecies border. Evolution 59:521-531. pdf (JSTOR)

Eckhart VM, Geber MA, McGuire C. 2004. Experimental studies of selection and adaptation in Clarkia xantiana (Onagraceae). I. Sources of phenotypic variation across a subspecies border. Evolution 58:59-7. pdf (JSTOR)

Eckhart, V.M., and M.A. Geber. 1999. Character variation and geographic distribution of Clarkia xantiana (Onagraceae): Flowers and phenology distibguish two subspecies. Madrono 46:117-125.

    student projects

  • Kramer, Heather Anu. 2008. Micro-scale controls of distribution and performance in Clarkia xantiana ssp. xantiana.
  • Montgomery, David. 2008. Niche modeling of the meso and macro distribution of Clarkia xantiana ssp. xantiana.
  • Chu, Anna. 2007. Soil compaction and texture controls on the local range limits of Clarkia xantiana ssp. xantiana.
  • Keledjian, Amanda. 2007. Water status of Clarkia xantiana ssp. xantiana: regional versus local controls of species borders.
  • Louthan, Allison. 2006. Edaphic characteristics and the range limit of Clarkia xantiana ssp. xantiana.
  • Singh, Indrani. 2006. Water relations and the species border of Clarkia xantiana ssp. xantiana.
  • Lindahl, Amy. 1998-1999. Experimental evidence of a trade-off between stress avoidance and competitive ability in annual plants.

    Pollination biology (breeding systems and flower color) - publications

Hart GM, Eckhart VM. 2010. Ecological separation in foraging schedule and food type between pollinators of the California wildflower Clarkia xantiana ssp. xantiana. Journal of Pollination Ecology 2:13-20. pdf (JPE)

Eckhart VM, Rushing NS, Hart GM, Hansen JD. 2006. Frequency-dependent pollinator foraging in polymorphic Clarkia xantiana ssp. xantiana populations: implications for flower colour evolution and pollinator interactions. Oikos 112:412-421. pdf (Wiley)

Fausto JA Jr, Eckhart VM, Geber MA. 2001. Reproductive assurance and the evolutionary ecology of self-pollination in Clarkia xantiana (Onagraceae). American Journal of Botany 88:1794-1800. pdf (JSTOR)

    student projects

  • Shannon, Laura. 2006-2007. Gene regulation underlying a flower-color polymorphism in Clarkia xantiana.
  • Lundberg, Matthew. 2005. Expression studies of anthocyanin biosynthesis in Clarkia xantiana flowers.
  • Cram, Jacob. 2004. Natural selection on two flower color polymorphisms in Clarkia xantiana ssp. parviflora.
  • Vigeland, Christine. 2004. Development and biochemistry of flower color in Clarkia xantiana.
  • Carter, Daniel. 2003. Petal spots in Clarkia xantiana (Onagraceae) are associated with reduced palatability to grasshoppers.
  • Carter, Daniel. 2003. Analysis of fine-scale spatial variation in the petal spot polymorphism in Clarkia xantiana (Onagraceae): Inbreeding produces finer, more variable structure.
  • Hart, Georgia M. 2003. Sources of variation in pollinator service to Clarkia xantiana (Onagraceae).
  • McCord, Aleia. 2002. Geostatiscal analysis of geographic variation in Clarkia xantiana (Onagraceae).
  • Brummel, Rachel M. 2002. Natural selection on flower color polymorphism in Clarkia xantiana (Onagraceae).
  • Marsh, Naomi. 2002. Opposing forms of frequency-dependent foraging choices in the pollinators of Clarkia xantiana (Onagraceae)
  • Cooper, Elizabeth. 2001. Genetic analysis of breeding system and subspecies differences in Clarkia xantiana(Onagraceae).
  • Fausto, James. 1998-2000. Reproductive assurance and the evolution of autogamy in Clarkia xantiana(Onagraceae).
  • Hansen, Joseph. 1999-2000. The maintenance of a flower-color polymorphism in Clarkia xantiana(Onagraceae). II. Field studies of selection on petal spotting.
  • La Grange, Ceanatha. 1999-2000. The maintenance of a flower-color polymorphism in Clarkia xantiana(Onagraceae). III. Quantitative genetics of petal spotting and herbivore resistance.
  • Southard, Sheryl. 1999. Flowers and stress: Flower size and water relations of Clarkia xantiana(Onagraceae).
  • Twieg, Elizabeth. 1998. The maintenance of a flower-color polymorphism in Clarkia xantiana(Onagraceae). I. Geographic and subspecies variation in morph frequencies.
  • Watkins, Stephen. 1997, 1998 Developmental basis of self-pollination in Clarkia xantiana(Onagraceae).