WEEDS  OF  WESTERN  PEPPERMINT  PLANTATIONS.  121 
with  two  plants,  which  proved  to  be  Erigeron  canadense,  Lin., 
and  EreeJithites  Meracifolia,  Raf.,  and  were  named  correctly  by 
Mr.  Ensign,  who,  to  use  his  own  words,  is  not  acquainted  with 
botany  ;  he  further  observed  in  his  letter  :  "  Peppermint  grown 
on  7iew  grounds,  or  those  just  cleared,  is  quite  likely  to  be  mixed 
with  true  fireweed  [Erechthites) ;  but  the  colt's-tail  (^Erigeron), 
commonly  known  among  farmers  here  as  fireweed'^  also,  is  far 
more  prevalent  in  our  mint  fields,  and  almost  always  is  the  cause 
of  what  is  called  '  weedy  oil,'  though  sometimes  it  may  contain 
Erechthites,  and  in  a  few  instances  the  distillation  of  rag-weed 
(Roman  wormwood). "f 
The  druggists  in  Mr.  E.'s  neighborhood  stated  that  he  Avas 
wrong  in  naming  the  plants  as  he  did ;  they  relied  on  the  U.  S. 
Dispensatory,  the  statements  of  which  are  based  upon  Mr. 
Stearns'  paper,  who  probably  never  saw  the  weed  growing  among 
peppermint,  and  merely  named  it  after  Gray,  whose  botany  con- 
tains the  ordinary  names  most  widely  known.  Mr.  Stearns' 
mistake  led  to  the  other  errors ;  but  it  is  to  be  regretted  that 
there  are  apothecaries  who  do  not  feel  sufficient  interest  in  medi- 
cal botany  as  to  be  able  to  tell  Erechthites  from  a  species  of 
Erigeron. 
Feeling  interested  in  the  subject,  I  corresponded  with  Mr. 
Ensign,  who  lives  in  the  mint  region  and  raises  peppermint;  he 
very  kindly  answered  several  of  my  queries,  and  since  he  is 
evidently  a  careful  and  shrewd  observer,  it  will  be  best  to  give 
such  portions  of  his  letter,  dated  Nov.  4th,  1869,  as  may  seem 
to  be  of  particular  interest,  and  may  serve  to  correct  the  errors 
of  others. 
"The  Erigeron,''  he  writes,  "  is  known  in  northern  Ohio  and 
this  vicinity  as  horse-tail,  mare's-tail,  colt's-tail  and  cow's-tail, 
besides  having  acquired  the  name  fireweed  in  this  locality.  It 
not  only  grows  among  mint,  but  springs  up  in  the  wheat  stubble 
and  pastures.  In  the  latter  it  grows  more  plentiful  the  first  year 
after  the  grain  crop  is  taken  from  the  land,  and  where  the  seed- 
ing is  light.  I  have  noticed  it  growing  plentifully  this  year  in 
an  old  sod  pasture. 
*  My  italics;  the  following  is  underlined  in  Mr.  Ensign's  letter.  J.  M.  M. 
\  Ambrosia  artemisioefolia,  Lin. 
