686 
Triticum  Repens. 
Am.  Jour.  Pharm. 
.  October,  1919. 
is  usually  oval  in  section,  and  at  each  end  of  the  oval  two  lacunae 
occur  in  the  cortex.  Within  the  sclerenchyma  a  large  number  of 
scattered  vascular  bundles  occur.  The  most  distinctive  feature  of 
this  rhizome,  however,  is  that  all  the  cells  of  the  ground  tissue  within 
Fig.  1.    Triticum  repens. 
the  sclerenchyma  have  comparatively  thick  walls  and  are  filled  with 
starch  grains  (Fig.  2).  Starch  does  not  occur  in  any  quantity  in 
any  of  the  other  species  examined.    This  starch  gives  a  character- 
Fig.  2.    Cynodon  Dactylon. 
istic  white  appearance  to  the  cut  surface  of  the  rhizome.  The  center 
is  frequently,  but  not  always,  hollow  as  in  couch  grass. 
Commercial  samples  can  be  examined  for  this  grass  very  easily. 
A  clean,  transverse  cut  with  a  sharp  knife  or  a  razor  displays  the 
