The invasive plant Spartina alterniflora (Atlantic smooth cordgrass) and its hybrids with native S. foliosa (Pacific cordgrass) have invaded over 170 marshes in the San Francisco Bay as of 2013. Past control efforts have extirpated both native and non-native Spartina from many marshes and been associated with decline in the endangered clapper rail, halting control efforts. This study will examine the effects of habitat components (elevation and inundation, substrate, marsh vegetation) and genotypes on S. foliosa phenotypes in the hopes of identifying a strain of S. foliosa most suited to habitat restoration efforts. Working with samples from eleven S. foliosa populations transplanted to controlled garden and greenhouse environments, the researchers will monitor plant performance and phenotypes before testing for a genetic basis for performance differences. The anticipated outcome is to identify the genotype of native S. foliosa that grows most rapidly and produces the most viable seed over the greatest range of environmental parameters.