Seed Polymorphism and Germination Ii. The Role of Hybridization in the Germination Polymorphism of Rumex Crispus and R. Obtusifolius

Summary. The morphology of Rumex crispus L., R. obtusifolius L. and putative hybrids was examined. There appeared to be evidence of introgressive hybridization, particularly with backcrossing to R. crispus. Seed germination in plants from a mixed population varied widely, but when plotted against the hybrid index for the parent plants the could be partially separated in respect of germination behaviour. Some of the polymorphism previously described may have resulted from inclusion in the tests, together with pure parental types, of plants of hybrid origin which had introgressed to such an extent that they were almost indistinguishable from the parent species. The implications of the discussed.