A light microscopic study was made of stems 5 cm in diameter from Indonesia. The lignified secondary wall of the vascular fibers consisted of about 7 alternating broad (1 mum) and narrow (0.2 mum) layers with a thin, lignin-rich isotropic transition zone between them. In longitudinal section, the fibrillar orientation of about 40° to the axis was reversed on passing from each layer to the next (i.e. showing parallel orientation in the 3 narrow layers). The structure is similar to that found in bamboo and cocoanut fibers and may contribute to the elastic properties of the rattan stem. -- AATA