Reversed phase HPLC has been applied to the isolation and quantitative distribution of valepotriates in roots and aerial parts of species and subspecies of the North American Genus PLECTRITIS (Valerianaceae) and in VALERIANA SITCHENSIS ssp. SCOULERI (Valerianaceae). A semipreparative Ultrasphere ODS column was used for separation and detection of small quantities of valepotriates in crude plant extracts.