Germination rate depends on seed origin, seed type, and seed weight:
There was no evidence for local adaptation at HD or HR for either cleistogamous or chasmogamous seeds (Fig. 3A). However, germination did depend on seed origin: at HD, nonlocal seeds sourced to the north of the garden significantly outperformed both local (HD) and nonlocal seeds sourced to the south of the garden (P < 0.001). At HR, nonlocal seeds sourced to the north significantly outperformed nonlocal seeds sourced to the south of the garden (P = 0.015), but local (HR) seed performance was not significantly different from either nonlocal seed group. Models for each pairwise combination between nonlocal source populations and common garden revealed the specific differences in germination by source population (Appendix C).
At both gardens, cleistogamous seeds significantly outperformed chasmogamous seeds (P 0.003; Fig. 3A), and seed weight was a significant positive predictor of germination (P < 0.001; Fig. 3B; Appendix H, Table 1). Despite this, cleistogamous seeds were universally lighter weight than chasmogamous seeds across all source populations (P < 0.001; Appendix D). There was no significant relationship between average seed weight and source population latitude (P = 0.559; Appendix E).