Identification of the wood species in the wooden sheath of Indonesian kris by synchrotron X‑ray microtomography

Abstract

A kris is a traditional dagger that originated in Indonesia. A kris is distinguished by its asymmetrical blade, which has layers of different metals bonded on its surface. Wood is the main material used to make the kris sheath. To preserve the knowledge about wood selection of the sheath, wood identification is a crucial first step. In the present study, we identified the wood species used to make the kris sheath. We performed synchrotron X-ray microtomography, which allows microscopic observation with minimum sample availability. Seven wooden kris sheaths were investigated. The results showed that synchrotron X-ray microtomography is suitable for observing the important microscopic anatomical features of the wood species in kris sheaths. We found that Dysoxylum spp., Tamarindus indica, and Kleinhovia hospita were used as sheath materials. We also visualized the spatial distribution of the prismatic crystals inside the T. indica and K. hospita xylem cells. Abundant crystals were present in T. indica arranged in longitudinal alignment inside the chambered axial parenchyma cells. The crystals were arranged in radial alignment inside the ray cells of K. hospita. The existence of abundant crystals in series may be important for the mechanical support of certain xylem cells.