Pharmacognosy of Thevetia peruviana bark

Abstract

Root and stem barks of Thevetia peruviana have many lenticels, scales, cracks and fissures on the outer surface; coarse striations and corrugations and networks on the inner surface and granular fracture. Sections show elongated stone cells in outer cortex and brachysclereids in secondary phloem; starch grains and long latex cells in secondary phloem; crystals in rays. Stem bark can be distinguished from root bark by the less developed cork. Barks of different varieties of the species can be distinguished by surface colour, nature of wrinkles, cork depth, abundance of latex cells, extent of the secondary phloem, phloem fibre length, ray-height, ray abundance, colour reactions to reagents and fluorescence.