Anatomy of two species of Plumbago : a traditional medicinal plant and its relevance for taxonomy

Abstract

Plumbago is a traditional medicinal plant in Ayurveda. The paper presents anatomical study of leaf, petiole, stem and root of two species of Plumbago namely P. zeylanica, P. auriculata and, its relevance in discrimination of these two species. Anatomical features of leaf which are of diagnostic value in delimitation of both taxa are outline of T. S.,shape and size of epidermal cells, presence of sclerenchyma surrounding the vascular bundles, number of tannins cells. Characters of taxonomic significance in petiole anatomy are outline of T. S, presence of trichomes, shape and size of epidermal cells, abundance of collenchyma, arrangement and number of vascular bundles, presence of sclerenchyma surrounding vascular bundles, number of tannin cells. The diagnostically useful anatomical features of stem to discriminate both taxa of Plumbago are degree of elevation of stem ridges, occurrence of double layered epidermis, size of epidermal cells, distinctness of endodermis, abundance and distribution of pericyclicsclerenchyama, number of vascular bundles. Anatomical features of taxonomic significance in root are width of cortex and abundance of starch grains in cortex cells, abundance and distribution of pericyclics clerenchyama, amount of vascularization, distribution, diameter and density of vessels, width of medullary ray.