Intraspecific variation in seed packaging.

Seed biomass, seed number and biomass of "packaging" (dispersal and protective devices associated with those seeds) were determined for 28 species of flowering plants. Individual variation in average seed packaging investment was marked in almost all species we surveyed. Furthermore, the pattern of biomass investment in dispersal devices and protective enclosures relative to associated seed biomass or seed number commonly differed among conspecific maternal parents: some individual parents invested more in dispersal and protection when associated seed biomasses or numbers were large, and others did not. Despite the variable relationships between seed biomass and packaging biomass within seed crops, individuals of most species varied sufficiently that significant positive correlations were found when all conspecifics were pooled. The widespread existence of such variation indicates a considerable potential for selection on seed packaging.