Am.  Jour.  Pharm  ) 
Mar.  1,1873.  j 
Manioc,  or  Tapioca  Plant. 
Ill 
state;  but  in  Brazil,  Guiana  and  Venezuela  many  undoubtedly  spon- 
taneous species  of  the  genus  Manihot  exist,  and  some  of  them  resem- 
ble the  cultivated  varieties  very  closely.  The  province  of  Goyaz  in 
Brazil  produces  the  largest  number  of  species,  and  amongst  those  of- 
fering the  closest  points  of  resemblance  are  M.  pasilla,  M.  flabellifo- 
Ua,  M.  digitiformis  and  M.  triphylla.  Pohl  describes  the  sweet  (non- 
poisonous)  manihot  (called  Aipi  in  Brazil,  M.  Aipi,  Pohl),  as  a  dis- 
tinct species  from  the  poisonous  manihot  (Yuca  brava  or  Mandioca 
brava  of  the  Spanish  and  Portugese  colonies) ;  but  the  author  agrees 
with  Goudot  in  thinking  that  they  are  only  varieties  of  the  same 
species. 
The  manioc  or  cassava  plant  is  propagated  by  cuttings  which  grow 
with  extreme  facility.  The  plant  appears  at  first  as  a  straight  stem, 
furnished  with  large  digitate  leaves,  with  about  seven  lobes.  At  the 
age  of  from  six  to  ten  months,  and  when  from  one  to  two  metres  high, 
it  throws  off  from  its  summit  lateral  branches,  with  smaller  leaves, 
and  shortly  afterwards  bears  flowers.  The  root  then  commences  to 
develop  several  elongated  amylaceous  tubers,  which  continue  to  grow 
underground  as  long  as  the  branches  yield  leaves  and  flowers.  At  the 
end  of  a  year  and  a  half  or  two  years  the  roots  are  ready  for  collec- 
tion ;  but  if  not  wanted  may  be  left  in  the  ground  for  some  time,  pro- 
vided they  be  watched  that  they  do  not  rot.  On  the  other  hand,  they 
may,  if  required,  be  gathered  earlier,  but  the  yield  is  not  so  good. 
The  stalks,  which  are  planted  about  a  metre  apart,  usually  produce 
two  or  three  tubers,  varying  in  size  and  weighing  together  from  one 
to  three  kilograms.  The  plant  is  not  very  choice  as  to  soil,  but  flour- 
ishes most  in  freshly  cleared  ground,  and  prefers  well- drained  spots,  an 
excess  of  moisture  causing  it  to  rot.  Although  living  for  two  or  three 
years,  the  plant  is  not  strictly  a  perennial,  since  it  becomes  gradually 
exhausted  as  the  tubers  attain  their  full  size.  The  sweet  manihot  is 
usually  gathered  earlier,  since  the  root  becomes  hard  and  bad  if  left 
to  develop  too  much. 
The  yield  of  the  manioc  root,  considering  the  time  it  occupies  the 
ground,  when  compared  with  other  farinaceous  roots  is  not  great ;  but 
on  the  other  hand,  it  contains  less  water  than  any  other  starchy  root ; 
— when  mature,  less  than  sixty  per  cent.  Its  texture  is  very  dense 
and  compact.  It  contains  much  starch,  and  its  richness  in  albumen 
and  other  nitrogenized  matters  is  estimated  at  two  per  cent.  In  con- 
verting the  roots  into  an  edible  flour,  they  are  scraped,  peeled,  and 
