1 62  The  Apocynacecz  in  Materia  Medica.  {Ami/£ch,F\^rrn' 
of  the  Q.  bianco.  The  Quebracho  Colorado  is  the  wood  of  a  Terebin- 
thaceae,  the  Loxopterygium  Lorentzii  Grisb.  The  Quebracho  Blanco 
is  an  Apocynaceae,  the  Aspidosperma  Quebracho  Schlecht  (Macagha 
Quebracho  H.  Bn.). 
The  discovery  of  the  tree  known  as  Quebracho  Blanco  is  due  to 
Burmeister,  who  considered  the  two  sorts,  white  and  red,  but  two 
varieties  differing  simply  in  a  few  details,  among  others  the  color  of 
their  wood.  Schlechtendal  gave  to  the  tree  the  name  Aspidosperma 
Quebracho,  but  he  continued  the  red  sort  under  the  name  A.  Que- 
bracho Colorado.  Ten  years  later,  Griesbach  recognized  in  the  red 
Quebracho  a  Terebinthaceae  of  the  group  Anacardium  and  assigned 
the  name  Loxopterygium  Lore7itzii,  in  honor  of  Professor  Lorenz,  of 
Cordoba.  Many  of  the  specimens  arrived  in  Europe  without  spe- 
cific name  or  precise  information  as  to  botanic  origin,  leading  to 
serious  confusion  and  diverse  results  in  clinical  experiments  with 
this  important  drug. 
All  the  Aspidosperma  are  from  tropical  America.  The  Quebracho 
abounds  particularly  in  the  Argentine  Republic,  and  more  especially 
in  the  district  of  Catamarca.  It  extends  to  the  south  as  far  as  the 
north  of  Patagonia.  The  Loxopterygium  seems  rather  to  belong  to 
the  province  of  Corrientes. 
The  genus  Aspidosperma,  Mart,  et  Zucc,  is  formed  of  shrubs  or 
trees  of  tropical  America  with  solid  wood,  leaves  ordinarily  alternate 
and  with  small  flowers  in  cymes,  with  one  or  two  ligneous  dehiscent 
follicles,  and  with  seeds  exalbuminous  and  winged. 
The  Aspidosperma  Quebracho  is  an  evergreen  tree  with  very 
straight  trunk,  attaining  the  dimensions  of  1 5  m.  in  height  and 
1-20  metres  in  diameter.  The  branches  are  long  and  flexible,  re- 
curving toward  the  ground,  giving  the  tree  the  appearance  of  a 
weeping  willow.  The  bark,  the  wood  and  the  leaves  are  rich  in 
tannin,  bitter  and  astringent. 
The  bark  of  Quebracho,  as  collected,  dried  and  shipped  to  Europe, 
appears  in  thick  fragments,  little  bent,  nearly  flat,  evidently  collected 
for  the  most  part  from  old  plants.  One  writer  says  that  the  trees  em- 
ployed are  more  than  seventy  years  old.  These  fragments  vary  in 
thickness  between  y2  and  3^  cc,  and  with  the  suber  more  or  less 
developed. 
The  exterior  face  is  very  rugose,  irregularly  marked  by  deep 
fissures.    The  color  varies,  even  in  the  same  fragment,  from  grayish 
