Clematis is a large cosmopolitan genus of more than 300 species. With a distribution that spans all continents save Antarctica, members of the genus have been sought after by horticulturalists the world over. Due to such intense interest the classification of Clematis has been revised numerous times over the last 300 years. The most widely accepted, current, classification based on traditional morphology was put forth by Tamura in 1968, revised in 1989, and modified further by Johnson in 1997. This classification is based largely upon floral characteristics such as size, shape and color as well as minor differences in vegetative and inflorescence morphology. Essig in 1990 suggested an alternative classification scheme based upon seedling morphology and reproductive compatibility. Essig proposed two natural groups which would encompass the traditional sections. Sequences of the chloroplast encoded trnL intron and trnL-F intergenic spacer were examined to test which hypothesis accurately represents the phylogenetic relationships within the genus. The two chloroplast regions (approx. 720 bp.) will be augmented with matK, also chloroplast encoded, sequence data as well as a morphological data set. Preliminary sequence analysis of ten ingroup taxa and one outgroup taxa (Anemone spp.), utilizing the trnL intron and trnL-F intergenic spacer regions, shows moderate support for Essig's "seedling hypothesis". These findings provide insights into characters that could potentially hold vast amounts of phylogenetic information within this group.

Key words: Chloroplast, Clematis, Phylogeny, Ranunculaceae, trnL intron, trnL-F intergenic spacer