Hybridization of Vernonia Acaulis and V. Noveboracensis (Compositae) in the Piedmont of North Carolina

ABSTRACT
Jones, S. B., Jr. (Department of Botany, University of Georgia, Athens, 30601). Hybridization of <em>Vernonia acaulis</em> and V. <em>noveboracensis</em> (<em>Compositae</em>) in the Piedmont of North Carolina. Two seasonally and ecologically isolated species of <em>Vernonia</em> were found to be hybridizing in Montgomery and Randolph Counties, North Carolina. Man has broken down the ecological isolation by clearing the forest and cutting roads through this area. Origin of the natural hybrids was documented by the production of artificial F1 hybrids. Meiosis was normal and pollen stainability was high in both the hybrids and the parents. Local population samples were made and the morphological characters of the parents and their hybrids were compared. Chromatographic studies detected backcrosses which would have been overlooked on the basis of gross morphology. The occurrence of F1’s, plus BC’s and presumably successive BC’s may allow a limited, but possible route for some gene flow between the two parent species.