The  common  wheat  (Triiicum  vulgar e}  (Fig.  154)  is  an  an-
nual plant  which  is  grown  very  extensively  for  the  grain.
*  Shrubs  or  tree-like  in  the  bamboos.
t  Corn  is  a  member  of  the  grass  family  with  a  solid  stem.
312


MONOCOTYLEDONES


313


roots  are  fibrous,  the  stems  hollow  ai^d  closed  at  the  nodes,  the
leaf  of  the  typical  grain  type,  the  inflorescence  of  spikelets  ar-
ranged on  a  spike,  which  is  frequently  referred  to  as  the  head.
The  axis  or  rachis  of  the  spike  is  zigzag,  the  spikelet  being  at-
tached on  the  outer  or  convex  side  of  the  curve  and  resting  in  the
concave  side  next  above.  Each  spikelet  contains  from  two  to
five  flowers,  but  usually  only  two  grains  reach  maturity.  Each


F


FIG.  154. — Six  types  of  wheat.     Top  row,  durum.  Polish  wheat,  and  white  winter.     Bottom
row,  red  winter,  hard  winter,  and  hard  spring.     (Productive  Farm  Crops.)

flower  consists  of  one  pistil,  with  two  stigmas,  three  stamens  and
two  glumes  (the  outer  or  lemma  and  the  inner  or  palet}.  The
entire  spikelet  is  enclosed  between  two  glumes.  The  lemma  and
the  palet  are  sometimes  spoken  of  as  fertile  glumes  and  the  two
outside  glumes  as  empty  glumes.
