PHARMACEUTICAL BOTANY 



Wood. From a pharmacognic standpoint as well as that of the 

 lumber trade, wood is all that portion of woody exogenous plant 

 axis inside of the cambium line. In Dicotyl and Gymnosperm 

 stems it therefore includes the xylem regions of the bundles, the 



FIG. 76. Photomicrograph of transverse section of Cascara Sagrada bark; 

 k, cork; g, cork cambium; c, cortex; st, group of stone cells; bf, group of bast fibers; 

 mr, medullary ray. 



xylem portions of the medullary rays and the pith, while in the roots 

 of secondary growth of these plants it comprises the xylem portions 

 of the bundles and the xylem medullary rays. 



As the cambium year after year adds new layers of wood to that 

 already present on its inner face, the coveying of sap and storing 



