Huston, MichaelBirnbaum, Amanda2012-08-152012-08-152012-08Birnbaum, A. (2011). <i>Plant growth and chemical responses to variation in soil properties by a Texas sand ridge endemic Monarda viridissima (Lamiaceae)</i> (Unpublished thesis). Texas State University-San Marcos, San Marcos, Texas.https://hdl.handle.net/10877/4329I measured the growth rate, germination rate and volatile oil content of Monarda viridissima grown in two soil types from its native habitat, a non – native soil, and a peat – based soil mixture to determine if there were differences between treatments and among individuals. I also measured the volatile oil content and vegetation structure at the two native M. viridissima field sites to determine whether there were differences between populations of M.viridissima and Monarda punctata. Comparisons of edaphic endemics to their closest relatives are useful for revealing factors that differ between the two species as well as the mechanisms that may cause the congeners to retain distinct populations. Analyses of the volatile oil content of the two species revealed significant differences in oil content and variability between the two species at different sites. Volatile oil content of M. viridissima across different edaphic conditions was diverse among individuals and between treatments. Growth and germination rates were significantly lower in the non-native soil type than in the native soils and peat – based soil mixture.Text61 pages1 file (.pdf)enEdaphic endemicMonardaLamiaceaeCarrizo formationTexasVolatile oilsThesis