Morphological Anatomy of Leaf and Rhizome in Zingiber officinale Roscoe, with Emphasis on Secretory Structures

The morphological anatomy of leaf and rhizome was studied at different developmental stages in Zingiber officinale Roscoe using both light and electron microscopy, with an emphasis on characterizing secretory structures. The results show that the leaf comprises epidermal cells, mesophyll cells, and vascular bundles. Oil and crystal cells are scattered throughout the parenchyma, and some are within or in close contact to the vascular bundle sheath. The rhizome consists of epidermis, cortex, and stele. The pericycle of the rhizome remains meristematic and produces tissues centripetally, whereas the endodermis has no meristematic activity. Starch grains vary in shape from round to oval and vary in size from small to large throughout rhizome development. Oil cells and cavities are scattered and cavities are of lysigenous origin. When mature, the starch grains decrease in abundance while an increasing number of oil cells and cavities are formed. This anatomic characterization provides a theory foundation for medicinal exploitation and utilization of Z. officinale Roscoe.