Seed weight is an important predictor of germination success
It is clear that seed weight is an important factor influencing the germination of both chasmogamous and cleistogamous seeds in our study. This is to be expected, as larger seed mass has long been linked to more energy investment and higher germination rates (Green & Hansen 1969, Hendrix 1984, but see Kitchen & Monsen 1984), although the tradeoff between seed size and dispersal ability, seed number, and susceptibility to predation all mitigate the overall fitness benefits of increased seed size (Gómez 2004, Gundel et al. 2012). Chasmogamous seeds of D. californica are heavier than cleistogamous seeds, but it was the cleistogamous seeds that generally outperformed chasmogamous seeds in our study. Our hypothesis that nonlocal chasmogamous seeds would outperform nonlocal cleistogamous seeds was primarily motivated by the genetic differences between seed types, although we would expect seed weight differences between seed types to reinforce this prediction. We were surprised to find the reverse phenomenon to be true across all three source groups in the HD common garden, with a significant seed type effect showing that non-local, obligately selfed, smaller cleistogamous seeds significantly outperformed non-local, potentially outcrossed, larger chasmogamous seeds.