18  The  Japanese  Peppermint  Plant         { ^'"'ja^'n  "^188^"*^ 
sis  f.  pi'perascenSy  differing  from  M.  arvensis  as  described  by  Babingtoii 
in  having  the  calyx  teeth  longer  than  broad^  and  in  the  upper  leaves 
being  gradually  smaller;  from  M.  sativa,  in  the  leaves  having  longer 
stacks  and  tapering  below ;  from  3L  Javanica,  in  the  uppermost  leaves 
being  more  than  twice  (usually  six  or  eight  times)  as  long  as  the  verti- 
cillasters,  and  in  the  veins  being  hairy  on  the  under  surface  of  the 
leaf  whilst  those  on  the  calyx  are  erecto-patent ;  and  from  31,  cana- 
densis, in  the  reflexed  pubescence  of  the  stems. 
With  respect  to  the  Chinese  peppermint  plant,  it  so  exactly  agrees 
watli  the  specimen  of  llentha  canadensis,  var.  glabrata,  furnished  to 
me  by  Dr.  A.  Gray,  that  if  the  latter  be  a  typical  specimen'  I  can 
only  consider  that  it  should  be  referred  to  M.  arvensis,  under  the  name 
of  if.  ai'vensis,  var.  glabrata. 
Dr.  Gray's  specimen  has  the  calyx  teeth  much  shorter  than  those  of  the 
typical  31.  canadensis  sent  at  the  same  time,  and  the  hairs  on  the  stem 
and  pedicels  are  reflexed,  while  those  of  the  calyx  tube  are  erecto-patent. 
There  are  some  other  points  in  connection  with  peppermint  which  are 
extremely  suggestive,  and  to  which  I  desire  to  call  the  attention  of  those 
who  have  greater  ability  and  more  time  for  investigation  than  myself^ 
A  number  of  varieties  and  forms  of  so-called  species  possess  the 
same  odor  and  flavor,  as  shown  in  the  following  list : 
3fentha  piperita,  3fentha  arvensis,  var.  piper ascens,  31.  canadensis,, 
var.  glabrata  (!),  and  31.  incana  (!),  cultivated  near  Bombay  for  pro- 
ducing peppermint  oil  (Dymock). 
Spearmint,  3Ientha  viridis,  L.,  3fentha  sylvestiis  (!),  rotundifolia  (!) 
sylvestris  ( ! ),  canadensis  ( ! ),  31.  arvensis,^  var. 
The  questions  then  arise : 
1st.  Do  the  oils  of  these  species  differ  among  themselves,  as  ha& 
been  shown  to  be  the  case  with  those  of  if.  piperita  and  31.  arvensis,, 
var.  piperascensf^ 
2d.  If  so,  is  this  difference  dependent  on  degree  of  development,  on 
climate,  soil,^  or  sex? 
^Dr.  Franchet  notes,  in  his  "Flore  du  Japan,"  the  reflexed  leaves  in 
some  specimens  of  M.  canadensis. 
2  Those  marked  ( ! )  have  been  tasted  by  myself. — E.  M.  Holmes. 
3"Pharm.  Jom\"  (3),  ii,  p.  321. 
*Mr.  J.  Lloyd  found  a  variety  of  31.  aquatica  possessing  a  lemon  odor  on 
calcareous  soil  near  the  sea,  and  M.  Malinvaud  a  specimen  of  M.  arvensis 
with  a  lemon  odor  in  a  ditch  near  Ivry,  where  other  plants  of  the  same 
species  possessed  only  the  usual  odor  of  the  plant. — Bull.  Soc.  Bot.,  1881^ 
p.  370. 
