Pharmacognostical Studies on Siddha Medicinal Plant Boerhaavia diffusa L.

Boerhaavia diffusa, commonly known as punarnava in Sanskrit and Mukkarattai in Tamil, is a herbaceous plant of the family Nyctaginaceae. The whole plant or its specific parts (leaves, stem, and roots) are known to have medicinal properties. In Siddha system of medicine it is used as expectorant, diuretic, laxative, refrigerant, anthelmintic and emetic. Leaves opposite in unequal pairs, larger ones 2.5 -3.8cm long and smaller ones 1.2 – 1.8 cm long, ovate, oblong or sub orbicular, apex rounded or slightly pointed, base subcordate; petiole long, nearly as long as the blade, slender. Microscopically, T.S of lamina is dorsiventral in structure, Stomatal index for adaxial epidermis 11–14, abaxial epidermis 10–13, vein islet number 9–15 and palisade ratio 3 to 6. The presence of Kranz anatomy, Tannin idioblasts, crystalline granules of Calcium oxalate, idioblasts containing raphides, ranunculaceous stomata on both the surface of the leaf are therefore diagnostic characters to identify Boerhaavia diffusa.