An ecotaxonomical study of swertia Linn. species of Trashigang district in Bhutan and their potential uses

The study focuses on the ecotaxonomical aspects of Swertia Linn. species in Trashigang Dzongkhag. The occurrence, distribution, morphological variations and other identifiable features besides ecological preferences were studied. In total six species of Swertia Linn. were recorded from the area of the study, viz. Swertia chirayita. (Roxb. ex Flem.) Karst., S. bimaculata (Siebold & Zuccarini) Hook. f., S. cordata. (G. Don) Clarke, S. teres (G. Don). J. Shah, S. nervosa (G. Don) Clarke and one species of Swertia with doubtful identity was also observed. It is interesting to note that Swertia chirayita (Roxb. ex Flem.) Karst. prefers to grow on the north facing slopes. The chemical constituents, ethnobotanical uses and antimicrobial assay also comprise the subjects of this paper. The phytochemical screening has revealed that all the species recorded have similar medicinal potential to that of S. chirayita (Roxb. ex Flem.) Karst. as most of the active principles identified through TLC were the same. The antimicrobial assay of Swertia bimaculata (Siebold & Zuccarini) Hook. f. and S. chirayita (Roxb. ex Flem.) Karst. against two strains of bacteria namely E. coli and Staphylococcus aureus, showed positive response. The future prospects of the genus in Bhutan have also been discussed.