In both Europe and the United States, a shortage of native plant material frequently precludes successful restoration. Native plant materials are needed to restore ecosystem functioning and services, provide for in situ conservation of biodiversity (e.g., Hobbs and Cramer 2008), maintain genetic diversity (Bischoff et al. 2010), and afford resistance to invasive species. Long-term stewardship goals are to create diverse, resilient systems with the genetic diversity and structure to facilitate adaptation to climate change and other environmental perturbations (e.g., Johnson et al. 2010). Commercial seed mixtures of non-native species and genetically uniform varieties threaten local diversity. Consequently, efforts to develop native seed sources are receiving considerable attention.