228 RHIZOMES AND ROOTS. 



(109) Galangal Rhizome. 



The rhizome of Alpinia officinarum, Hance (N.O. Scitaminese). 

 The rhizome presents the following structure : 



(1) Epidermis, the cells of which are tabular in transverse 

 section, but polygonal and straight walled in surface view. 



(2) Cortex, the cells of which have thickened, pitted, brown 

 walls and are tangentially elongated in the outer part of the 

 cortex but irregularly polygonal near the stele. It is tra- 

 versed by scattered fibrovascular bundles containing spiral, 

 annular and pitted vessels supported by a sheath of thickened 

 pitted fibres. In each bundle a narrow tube filled with a 

 brown secretion may be observed. 



(3) Stele, which is separated from the cortex by a distinct 

 ndodermis. The stele is composed of rather thick-walled 

 parenchymatous tissue traversed by fibrovascular bundles. 



The parenchyma of both cortex and soele contains an abun- 

 dance of starch grains and scattered rounded or polygonal cells 

 containing brown oleoresin. The starch grains vary from 18 

 to SO/* in length and from 7 to 15^t in width ; they are simple 

 and elongated oval or flask-shaped ; both hilum and striations are 

 very distinct. 



The diagnostic characters of powdered galangal rhizome 

 are : 



(a) The starch grains. 



(6) The reddish brown oleoresin. 



(c) The sclerenchymatous fibres. 



(d) The absence of calcium oxalate. 



