Systematic and ethnopharmacognostic investigation of selected medicinal plants of family Asteraceae

The present research project includes the family Asteraceae comprising the speciesCalendula arvensis L., Parthenium hysterophorus L. and Silybum marianum (L.) Gaertn. The present study was carried out to clear up the taxonomic position of the selected taxa and their authenticity. Medicinal plants face the problems in their identification due to confusion in nomenclature, taxonomic ranking and differentiation of various species at specific level sometimes at generic level also, but these problems can be overcome by using classical and applied approaches of taxonomy. Classical approaches are morphology, anatomy, palynology, ultra violet (UV) and infra red (IR) analysis and organoleptography whereas the applied approaches include their chemical analysis. In the context of morphology, characters such as calyx and corolla shape and size, flower color, shape and size etc showed variation. Leaf epidermal anatomy was found taxonomically useful. Epidermal cells show the difference in shape of epidermal cells, subsidiary cells, guard cells, micro-hairs and macro-hairs. All the three taxa can be distinguished easily on the basis of stomata type and width found useful in the delimitation of the taxa. Pollen characters were also studied including shape and size of pollen grains in equatorial and polar view. UV, IR and organoleptography analysis also showed a lot of variations among the selected taxa. The fluorescence, solubility and chemical analysis was also done in order to delimit the taxa. All these parameters showed successful findings and can be helpful for the identification, authentication and classification of the selected plants. All the available records are listed and mapped.   Key words: Morphology, anatomy, palynology, organoleptography.