1  lo  Constituents  and  Properties  of  Potentilla.  {^""■Jan/iSys'"'' 
of  tannin,  from  which  the  so-called  tormentil-red,  the  red  coloring 
matter  of  the  drug,  which  is  likewise  present  to  the  extent  of  about 
one-sixth  of  the  weight  of  the  rhizome,  is  probably  a  derivative. 
Similar  constituents  will  doubtless  be  found  in  the  roots  and  herbs  of 
the  plants  which  are  botanically  allied  to  the  genus  Potentilla^  if  we 
may  be  allowed  to  judge  from  their  sensible  properties  ;  the  following 
plants  of  the  suborder  Dryadeae  (De  Candolle's  tribes  of  Sanguisorbeae 
and  Dryadeae)  contain  in  their  roots  and  herbaceous  portions  very  little 
or  no  volatile  oil,  as  is  evidenced  from  their  slight  odor,  but  they  possess 
a  more  or  less  marked  astringent  taste,  in  some  cases  accompanied  by 
some  bitterness  :  Geum  rivale^  Lin.,  and  G.  urhanum^  L.,  or  avens  ; 
Poterium  sanguisorha^  Lin.,  and  Sanguisorha  officinalis^  L.,  or  burnet  ; 
Alcheinilla  aphanes^  Laers  (s.  Aphanes  arvensis^  Lin.),  and  A.  vulgaris^ 
L.,  or  lady's  mantle;  Agrimonia  eupatoria^  Lin.,  or  agrimony,  and  Rubus 
villosus^  Alton,  and  R.  cayiadensis^  Lin.,  the  North  American  blackberry 
and  dewberry,  the  rootbark  of  which  is  officinal  in  the  U.  S.  Pharma- 
copoeia. 
Of  the  genus  Potentilla^  of  which  about  one  hundred  species  are 
enumerated,  tormentil  is  the  only  one  occasionally  still  used  in  medicine, 
though  formerly  several  species  now  obsolete  have  been  employed. 
Potentilla  anserina^  Lin.,  silver  weed,  is  indigenous  to  Euiope  and  the 
northern  portion  of  the  American  continent.  Both  the  herb  and  the 
perennial  root  have  a  mild  astringent  taste,  and  are  said  to  have  been 
used  by  the  Indians  as  an  antidote  to  snake-poison  ;  while  in  Europe,  it 
was  employed  in  diarrhoea,  hemorrhages,  pulmonary  complaints,  some 
hepatic  disorders  and  in  dropsy.  The  leaves  are  radical,  interruptedly 
pinnate  ;  the  leaflets,  9  to  19  in  number,  oblong,  deeply  serrate,  silvery 
white  and  downy  underneath. 
P.  fructicosa^  Lin.,  shrubby  cinquefoil,  likewise  inhabits  the  northern 
portions  of  the  Northern  hemisphere.  The  five  to  seven  pinnae  are 
linear  to  lanceolate  oblong,  entire,  silky  underneath,  and  have  a  mild 
astringent  and  bitterish  taste.  They  are  used  by  some  Siberian  tribes 
like  tea,  and  were  formerly  reputed  to  possess  febrifuge  properties  ;  ex- 
ternally, the  leaves  were  used  as  a  vulnerary. 
P.  rupestris^  Lin.,  is  a  native  of  mountainous  regions  of  Europe  and 
Siberia.  The  radical  leaves  are  pinnate,  and  the  stem-leaves  usually 
three-lobed  \  they  have  an  astringent  taste  and  are  used  in  Siberia  like 
tea. 
P.  palustris^  Scop.  s.    Comarum  palustre^  Lin.,  marsh-cinquefoil, 
