Crystallomorphic diagnosis of medicinal plants and their adulterants

The global level revival of enthusiasm in the alternative system of therapy, especially the renewed trends towards the herbal   based indigenous formulations, has landed in the execution of certain mandatory measures. Of several such precautionaries, detection and prevention of intentional adulteration, maintenance of quality control of the herbal drugs assume primary exigence. Botanical determination of the genuineness of the herbal drugs, beyond any doubt, is the primary step before subjecting the drugs for pharmaceutical evaluations. Several botanical techniques are accessible to authenticate the identity of the herbal drugs, and application of crystallomorphic divergence is a simple but effective strategy for checking the original drugs from their adulterants. Calcium Oxalate Crystals are accredited with the phenomeon of pleomorphism and the physical property of birefringence. Added to it, the crystal habits are restricted in distribution among the plants and sometimes, specific to certain Angiosperm taxa. Further, the crystals in plant cells are easy to detect microscopically, especially under polarized light. On these merits, the morphological dimensions of the crystals and their dynamics in relation to different plant groups offer a helping hand in herbal drugs standardization. The present paper highlights the crystallomorphic spectrum and gamut of variation of the crystal scenario among the medicinal plants. The major types of crystal include prismatic, spiny spheroids or the druses, smooth spheroides (polyhedrals), rosettes, styloids, solitary acicular, bundled acicular or raphides and sand or microcrystals.  A new crystal type, namely, scalloped crystal has been recognised and added to the list. Citing specific crystal habits form the survey, a protocolic technique of application of crystallography in identification of important medicinal plants and detecting their adulterants is presented. The elite of those medicinal plants drawn from the list of renowned herbals used in ISMO are opted to illustrate the crystal specificity in relation to drug identity.