Anatomical Studies on the Resiniferous System in Boswellia Serrata Roxb. Trees

Resin canals in Boswellia serrata are long tubular structures which ramify both vertically and horizontally in the tree. Although, they are present in all parts of the stem, viz., bark, wood and pith, they are most abundant in the bark where both vertical and horizontal types occur. In the wood, only horizontal canals are present while in the pith only vertical canals are found. In the bark the vertical canals branch freely and some times also anastomose in the parenchymatous regions of the phloem. These are also connected with the horizontal ones which are again continuous from the bark to the wood. These horizontal canals confined to the rays, are unbranched and mostly appear to end blindly in the weed. A few of these, hcwever, run along the entire radii of the wood being connected with the vertical canals of the pith. The latter, however, are short unbranched structures only. All these canals originate schizogenously, but branching of the canals is accompanied by certain amount of cell disintegration. Blazing the tree for the gum-oleoresin does not affect the structure of the bark or wood to any great extent except that the number of horizontal canals increases appreciably in the new tissues formed after tapping both in the bark and the wood.