Ballota  Hirsuta.  {  AmMJa°rch,  \\%n 
branched  hairs  (Fig.  8).  These  are  easily  distinguished  from  those 
of  Marrubium  vulgare  by  their  generally  longer  basal  stalks,  thicker 
walls  and  more  rigid  looking  branches.     As  many  as  eighteen 
Fig.  7.  Cross  section  of  foliage  leaf  of  Ballota  hirsuta  made  through  a 
stronger  nerve  and  portion  of  the  lamina,  up.  e.,  upper  epidermis;  I.  e.,  lower 
epidermis;  pal.,  palisade  parenchyma;  sp.  p.,  spongy  parenchyma;  s,  stoma; 
col.,  collenchyma;  si.,  sieve  tissue;  tr.,  trachea;  wf.,  wood  fibers;  bt.,  branched 
trichomes ;  gbt.,  branched  trichome  with  central  branch  the  longest  and 
bearing  a  two-celled  glandular  head ;  gt1,  gt2,  gt3,  glandular  trichomes. 
X98. 
branches  have  been  counted  emanating  from  the  central  stalk.  The 
shortest  branches  arise  from  the  basal  portion,  the  rest  becoming 
longer  as  the  stalk  is  ascended.  Most  of  the  branches  vary  from 
one  to  three  cells  in  length.  The  central  or  longest  branch,  how- 
ever, may  be  uniseriate  four-celled  and  attain  a  length  of  3  Mm. 
