Taxonomy of the genus Scrophularia (Scrophulariaceae) in Korea

Abstract

Inter-specific relationships among six species and two varieties, belonging to Scrophularia (Scrophulariaceae), in Korea were re-examined based on both morphological and molecular data. Scrophularia takesimensis, a Korean endemic species, should be separated from S. grayana as an independent species based upon unique morphological characters such as non-winged stems, thickened leaves and glabrous surfaces of leaves, even though they share a lot of other features. It was found that S. grayana is distributed in Sokcho in Korea and along the coast of the East Sea north to far eastern Russia. Although some morphologies of three taxa, S. cephalantha, S. koraiensis var. velutina and S. kakudensis var. microphylla appeared to differ from each other, their ITS DNA sequence data was similar to that of S. kakudensis, suggesting that they might better be designated with the later species. The taxonomic position of S. koraiensis, only found in Korea, has been ambiguous, but ITS DNA sequence data in this study revealed that this species is distinct from S. kakudensis. Consequently, we conclude that the genus Scrophularia in Korea includes five species.