The  fruit  of  the  pignut  hickory  varies  still  more  in  shape
than  that  of  the  other  hickories,  and  hardly  less  in  size.  It  is
sessile  on  a  short  terminal  stalk,  and  most  commonlv  pear-
shaped  ;  at  least,  that  is  the  shape  which  I  have  found  most
common  in  Massachusetts,  and  that  almost  universally  con-
nected with  a  leaf  of  five  leaflets.  This  hjis  been  called  the
fig-shaped  {ficiformis)^  from  its  resemblance  to  a  fresh  fig.
Another  variety,  also  common,  has  the  fruit  nearly  round,  but
often  irregularly  shaped ;  and  a  third,  less  common,  has  a  large
broad  fruit.  These  differences  in  the  shape  of  the  fruit  are
connected  with  corresponding  differences  in  the  leaves,  bark,

VOL.  I.  15


226  WOODY  PLANTS  OF  MASSACHUSETTS.
aud  appearance  of  the  tree,  inducing  several  botanists  to  con-
sider them  as  distinct  species.  Michaux  is  probably  right  in
making  them  only  varieties.  The  husk  has  a  smooth  or  granu-
lar surface,  with  seams  depressed  above  and  often  prominent
below,  and  sometimes  so  from  top  to  bottom,  extending  nearly
to  the  base,  and  dividing  it  into  four  unequal  lobes.  It  is  very
thin,  though  not  equally  so  in  all  the  varieties,  and  crustaceous,
but  not  hard.  The  nut  has  a  hard  and  tough  shell,  some-
times thin,  but  oftener  pretty  thick,  of  a  bluish  gray  color  and
smooth  surface.  The  kernel  has  at  first  a  hazel-nut  taste,
which  turns  presently  to  a  disagreeable  bitter.  Some  varieties
have  a  nut  almost  equal  to  an  inferior  shellbark.  The  nuta
grow  single,  or  two,  three,  or  four  together.  They  are  often
very  abundant,  several  bushels  being  produced  on  a  single
tree,  and  they  are  then  usually  found  growing  in  pairs.
