R. Muthukumarana¹, R.M. Dharmadasa^1,

Plectranthus hadiensis (Forssk.) Schweinf. ex Sprenger. and Plectranthus amboinicus (Lour.) Spreng. (Lamiaceae) are two medicinal plants with taxonomic ambiguity. Even though both plants are similar in appearance, their therapeutic properties are different. However, incorrectly use of these plants in herbal formulations might adversely effect on therapeutic properties of herbal drugs. Present study describes the comprehensive pharmacognostic aspects of P.hadiensis and P. amboinicus by means of physical and chemical yield parameters. Morphological, anatomical Thin Layer Chromatographic profiles, essential oil content and composition were carried out according to the established protocols. Plant fresh and dry weights of both species were increased with the maturity while dry fresh ratio was decreased. Physical and chemical yield parameters were optimum at fully matured stage. TLC finger print profiles exhibited nine spots for P. hadiensis while five spots for P. amboinicus and yellow green (Rf 0.73) spot was characteristic to P. hadiensis, while violet-blue (Rf 0.61) and brown- red (Rf 0.55) were characteristic spots for P. amboinicus. P-Cymene, Gerenyl acetate and geraniol were identified as common compounds for both species. Presence of higher chemical and physical parameters scientifically validates the traditional claims of harvesting of both plants at fully maturity stage. Results of the present study either singularly or as a whole could be incorporated for quality control and standardization of P. hadiensis and P. amboinicus.

Plectranthus hadiensis, Plectranthus amboinicus, Lamiaceae, Thin Layer Chromatography, Morphology, essential oil