Agamospermy, the asexual production of seeds, occurs in a wide variety of flowering plants. In groups where hybridization, polyploidy, and agamospermy are combined, an agamic complex is formed. The Crepis occidentalis agamic complex is among the best known and most frequently cited examples of an agamic complex. This research will use restriction site variation in chloroplast and nuclear ribosomal DNA, as will as allozyme variation, to examine the origin, development, and maintenance of this complex. The relationship of the North American taxa to other sections of the genus, the relationships among North American species, and the origins of polyploids within the complex will be evaluated with restriction site data. The genetic structure of the agamic population will be examined using allozyme variation. Results from this research will have implications for taxonomic treatment of this and other agamic complexes and will serve as a model for combining traditional and molecular methods in the study of agamic complexes in plants. This study will greatly add to the understanding of the adaptive radiation and spread of this group and help explain how genetic variation is introduced, distributed, and maintained in agamic complexes.
