Differences in Vegetative Characteristics Among Four Populations of Senecio vulgaris L. Possibly Due to Interspecific Hybridization

Abstract

Leaf vegetative characteristics of Senecio vulgaris plants were examined for evidence of introgression by Senecio squalidus. S. vulgaris plants are shown to be more similar to S. squalidus in an area of high S. squalidus frequency than elsewhere, but the expected greater similarity of the radiate form of S. vulgaris to S. squalidus is seen only in one of the three characteristics studied. A possible explanation for these latter results is given.