Unlike the culm hollow structure of most bamboo species, Oxytenanthera abyssinica has a unique solid or semi-solid culm, which may endow it with superior mechanical performance. In this study, the variation in fiber morphology and micro-mechanical properties across the radial regions of bamboo culm was examined by optical microscopy, scanning electron microscopy, X-ray diffraction, and nanoindentation. Results showed that the mean values of vascular bundle frequency and fiber tissue proportion were 1.76 pcs/mm${}^2$ and 21.04%, respectively, both of which increased gradually from inner to outer. The mean length, diameter, and length-diameter ratio of the fiber were 2.10 mm, 21.54 $\mathsf{\mu }$m, and 101.41 respectively. The mean indentation modulus of elasticity (IMOE) and hardness were 21.34 GPa and 545.88 MPa. The IMOE exhibited a significant increase from the inner to the middle region, and little change was observed from the middle to the outer region. There were slight fluctuations in hardness along the radial direction. The mean crystallinity and microfibril angle(MFA) of the fibers was 68.12% and 11.26 degrees, respectively. There is a positive correlation between cellulose crystallinity and the IMOE and hardness, while there is a negative correlation between the MFA and the IMOE and the hardness.

The relationship between the structure and mechanical properties of materials has been a hot topic. However, there is a lack of research on the relationship between the structure of rattan and its mechanical properties. This study investigated the anatomical structure and bending properties of Calamus zollingeri, a commercially important rattan species. Samples were collected from different radial positions of the stem and analyzed for their microstructural features and mechanical properties. The distribution and morphology of vascular bundles (VBs), parenchyma cells (PCs), vessels, and fibers were examined using light microscopy. Bending tests were conducted to determine the modulus of rupture (MOR) and modulus of elasticity (MOE). Stepwise linear regression analysis was employed to explore the relationship between structural features and mechanical properties. The results showed that the diameters, lengths and distribution densities of the vessel elements were 280.32 μm, 2163.56 μm, and 3.68 pcs/mm², respectively; the double wall thickness, lumen diameter, diameter, length, length–width ratio were 7.55 μm, 4.30 μm, 11.85 μm, 1569.39 μm, and 134.08, respectively; the tissue ratios of the vessel elements, fibers, sieve elements, and PCs were 22.76%, 20.5%, 4.83%, and 51.87%, respectively. The MOR of C. zollingeri was 55.77 MPa, while the MOE was 2669.11 MPa. The MOR of C. zollingeri was mainly affected by a double wall thickness of fiber and the tissue ratio of PCs, while the MOE was mainly affected by a double arm thickness of fiber and the tissue ratio of the vessel elements. This research provides valuable insights into the structure–property relationships of rattan, which can inform its optimal utilization in various applications.