Common Garden Experiment
We planted seeds at HD on September 29th, 2018, and HR on September 30th, 2018. In areas with mature D. californica individuals already present, we aligned 15-m transects with 1-m2quadrats alternating every other side of the transect (Appendix A; C,D), avoiding areas where large rocks were present. Each 1-m2 quadrat was divided into 100 planting cells of 1-cm2 each (Fig. 1B). If a cell was suitable for planting (i.e., with adequate soil and large adult plants absent), we installed 5.5-cm diameter, 1.25-cm deep PVC rings into the soil to define the planting area (Appendix A; C,D). We left approximately 10% of suitable cells undisturbed after ring installation as controls to allow for the detection of background D. californica germination from the natural population (Fig. 1B). In each of the remaining cells, we planted 25 seeds of a given type and maternal plant in a predetermined randomized order, thereby randomizing planting location.