56o 
Coriaria  myrtifolia  as  an  Adulterant.    {An^  £ 
O.  Mam  L.,"  and  he  "regards  the  Origanum  majoranoides  of 
Willenow  as  a  form  of  O.  Mara  with  stalked  leaves  and  white 
flowers."  He  likewise  points  out  as  a  significant  and  curious  fact 
"that  in  our  national  herbaria  only  cultivated  specimens  are  to  be 
found  under  the  name  of  Origanum  major  ana  L." 
This  all  tends  to  confirm  the  writer's  contention  that  in  any  of- 
ficial standard  that  may  be  adopted  for  sweet  marjoram,  due  allow- 
ance should  be  made  for  the  botanical  uncertainty  and  for  the 
variations  effected  by  climatic  conditions  and  by  cultivation. 
In  order  to  arrive  at  a  definite  conclusion  as  to  the  botanical 
source  of  the  foreign  leaf  fragments  admixed  with  this  lot  of  mar- 
joram, and  suspected  to  be  coriaria  leaves,  the  investigation  had  to 
be  confined  to  a  microscopical  study  of  the  structure  and  a  com- 
parison of  this  with  the  structure  of  marjoram  and  of  authentic 
samples  of  the  leaves  of  Coriaria  myrtifolia. . 
In  commercial  marjoram  many  of  the  leaves  are  usually  broken 
by  the  stripping  or  beating  process  employed  to  separate  the  stems 
and  by  the  compressing  and  baling  resorted  to  for  transportation. 
Nevertheless,  by  soaking  up  a  small  sample  a  sufficient  supply  of 
leaves  is  generally  obtained  to  permit  the  study  of  size,  shape  and 
structure  and  compliance  with  type  specimens. 
The  lower  stem  leaves  of  marjoram  are  larger,  rounded  to  ovate, 
with  hairy  petioles,  the  upper  become  smaller,  usually  ovate  to  ovate 
Fig.  4.    Upper  surface,  Sweet 
Marjoram  Leaf. 
Fig.  5.    Lower  surface,  Sweet 
Marjoram  Leaf. 
