Abstract

Six species of the most important commercial genus, Calamus, from the Western Ghats of Peninsular India were examined, representing (a) small (10 mm), (b) medium (10-18 mm) and (c) large (18 mm) diameter rattans. The species were: (a) C. metzianus, C. rotang, C. travancoricus(b) C. hookerianus, C. pseudotenuisand (c) C. thwaitesii. Fibre wall thickness and fibre percentage within the vascular bundles vary more than the vascular bundle size and number per unit area. Both fibre wall thickness and fibre percentage decrease consistently from the basal (older) to the top (younger) internodes of the stem and from the periphery to the centre at a given internode. The increase of wall thickness with age is more pronounced in fibres than in corticaland ground parenchyma. The thickening of fibre wall with increasing stem density results from the deposition of additional lamellae. This appears to impart stiffness and determines the breaking behaviour of rattan both within the stem