XVI International Botanical Congess

Three diploid species of Tragopogon were introduced from Europe to the Palouse region of eastern Washington and adjacent Idaho early this century. These species hybridized, and two allotetraploid species were formed: T. mirus and T. miscellus. The parentage of these tetraploid species is well documented, and the tetraploids serve as models for the study of polyploid evolution. Understanding the genetic, chromosomal, and molecular consequences of polyploidy requires a historical perspective, especially an understanding of the relatedness of the diploid progenitors. We have therefore reconstructed the phylogeny of Tragopogon, a largely Eurasian genus of about 50 species, using sequences of the internal transcribed spacers of the nuclear ribsomal DNA. DNA was obtained from herbarium specimens, some of which were over 100 years old.