A comparative study was performed on 12 species of the genus Veronica L. (Plantaginaceae sensu APG 2003, formerly Scrophulariaceae) namely Veronica persica, V. bachofenii, V. urticifolia, V. agrestis, V. austriaca, V. chamaedrys, V. officinalis, V. orchidea, V. spicata, V. beccabunga, V. hederifolia, V. prostrata. In these species we have determined the aucubin and catalpol content by using a H...