Abstract

Stem anatomy and certain physical properties of two Calamus species representing large and small diameter rattans of Kerala were investigated. The anatomical parameters examined were the number of vascular bundles per unit area, vascular bundle size, percentage of xylem and phloem tissues, cell dimensions, particularly metaxylem vessel diameter, fibre length and wall thickness, and fibre percentage. Most of these features varied from stem base to top with definite patterns. The most important determining factors of wood density and volumetric shrinkage were percentage of fibres, wall thickness/lumen diameter ratio, and metaxylem vessel diameter. However, fibre wall thickness was the single most important anatomical parameter that determines the physical behaviour of rattans. With more thick-walled fibres and narrower metaxylem vessels, the basal portion of the stem is harder, heavier and with a lower rate of shrinkage than upwards in the culm. Most of the anatomical