Calcium Oxalate Crystals and Leaf Anatomical Characteristics of Kaempferia galanga L.

Abstract

Kaempferia galanga L. is a medicinal herb and an ornamental plant of Thailand. However, it is in decline due to the reducing forest area. In this report, we used a light microscope, a scanning electron microscope equipped with an energy dispersive X-ray spectrometer (EDS) to study leaf surface, leaf anatomy and crystals in the cells of K. galanga leaves. The leaves have a unique fragrant because there are oil cells on the leaf surface which contains a lot of essential oils. In addition, the leaf surface showed numerous stomata, trichomes and oil cells. The amphistomatic type had stomata distributed on both abaxial and adaxial epidermal layers. Tetracytic stomata types were found on the abaxial epidermis layer more than on the adaxial epidermis layer. There are unicellular trichomes on leaf veins and specific characteristics on the leaf surface. Specifically, the mesophyll cells of leaf contained calcium oxalate crystals in the cells. We found four forms of calcium oxalate crystal including prismatic, rhombic, hexagonal and octahedron. EDS spectra and X-ray maps show that the crystals were composed primarily of calcium and oxygen. This study on leaf surface, leaf anatomy and calcium oxalate crystals in the cell was a preliminary investigation that could be used for plant classification and a baseline experiment for study medicinal plants and others.