Available at: https://digitalcommons.calpoly.edu/theses/1022
Date of Award
MS in Biological Sciences
Dr. Matt Ritter
Several subspecies of Monardella villosa (California Coyote Mint) have been distinguished on the basis of leaf thickness, shape, and trichome characteristics, yet many intermediates are known. We investigated morphological differences in natural populations of two subspecies (M. v. subsp. villosa and M. v. subsp. franciscana) in the Scott Creek watershed, north of Davenport, in Santa Cruz County, CA. Monardella villosa subsp. franciscana grows in coastal scrub in gulches and ocean terraces whereas subsp. villosa grows at more protected inland sites. Morphological difference between subspecies may be adaptations to these different habitats. I grew plants in a common garden at Cal Poly, San Luis Obispo to determine if the morphological differences were genetically based. I also conducted a reciprocal transplant of the two subspecies between inland and coastal populations to determine if they are locally adapted.
The morphological differences (leaf hair density and length as well as leaf base angle) between subspecies were maintained in the common garden, yet no patterns of local adaptation were observed in germination or survival of the subspecies in reciprocal transplants in the first year. However, Monardella is a perennial plant and fitness differences may exist in later life stages that I have not yet measured.