Key distinguishing characters (KDCs) of official (Boerhaavia diffusa L.) and commonly mistaken (Trianthema portulacastrum L.) sources of Mukkirattai of Siddha

Boerhaavia diffusa L. has been used extensively in Siddha system of medicine and is often confused with Trianthema portulacastrum L. due to morphological similarities. This particular study compares, analyses and identifies the key distinguishing features of the two whole plant drugs based on pharmacognostical and phytochemical aspects. The samples were studied for macroscopy, microscopy, physicochemical analysis, preliminary phytochemical analysis and HPTLC following standard procedures. Macroscopic studies showed few notable differences in macro-microscopy of root, stem, leaves and flowers of both the plants. Microscopically root, stem, leaf and petiole of both the plants showed differences in layers of cork, presence of crystals and medullary rays (in root), the thickness of cuticle, cortex and arrangement of vascular bundles (stem), presence of characteristic type of trichomes (leaf) and shape of the petiole. Powder microscopy showed differences in epidermis, crystal types and shape of pollen. Preliminary phytochemical analysis showed the presence of phenol, saponins and coumarins in B. diffusa and was not detected in T. portulacastrum. There were significant differences in the values of quantitative microscopy, physicochemical parameters and HPTLC of both the whole plant samples. The finding of this study will be helpful for the correct identification of the plant