Variation of quantitative anatomical characteristics in the culm of belangke bamboo (Gigantochloa pruriens)

The anatomical characteristics of the stem of belangke bamboo (Gigantochloa pruriens), which is native in North Sumatra, Indonesia, were examined to attain valuable information for identification and effective utilization. The number and type of vessel bundles and the fiber and metaxylem dimensions in the longitudinal (bottom, middle, and top) and radial (outer, central, and inner) directions of the bamboo culm were investigated by optical microscopy. The vascular bundles were distributed unevenly and arranged alternately, as shown by cross-sectional images of the culms. The proportion of vascular bundles in the culm decreased from the outer layer to the inner layer and tended to increase from the bottom to the top. Most vascular bundles were classified as type IV at the bottom and as type III in the middle and top parts. Fiber length and cell wall thickness tended to increase from the bottom to the top and from the inner layer to the outer layer. Metaxylem length and diameter increased from the outer layer to the inner layer and from the bottom towards the top of the stem. It was revealed that the anatomical characteristics of the belangke bamboo varied significantly in the vertical and radial directions.