676 
Leaves  of  Drosera  Filiformis. 
(  Am.  Jour.  Pharnu 
X  December,  1896. 
colored  hairs.  On  closer  inspection,  this  proved  to  be  the  small 
plantlet  which  nature  had  already  provided  for  the  next  year. 
The  Drosera  filiformis  is  evidently  a  perennial.  On  dissection,  the 
rudimentary  leaves  destined  to  form  the  rosette  of  leaves  of  the 
future  plant  were  found  closed  upwards  over  each  other  into  a  ball 
and  covered  with  the  mass  of  hairs,  presenting  almost  the  appear- 
ance of  a  small  bulb. 
At  this  stage,  the  leaf  is  green  in  color,  rather  thick,  lanceolate 
in  outline,  about  one-third  inch  in  length,  and  with  the  apex  dis- 
tinctly showing  the  circinate  tendency,  which  later  becomes  so  pro- 
nounced. 
Gray's  Manual  states  "  that  the  leaves  of  Drosera  filiformis  are 
filiform  and  with  no  distinction  of  petiole  and  blade,"  a  statement 
which  is  generally  concurred  in  by  other  authors.  Our  observations 
lead  us  to  the  conclusion  that  the  small  leaf,  as  it  appears  at  this 
stage  of  growth,  really  constitutes  the  blade  or  lamina  of  the 
sessile  leaf,  and  that  the  future  growth  of  the  leaf  is  entirely  an 
extension  of  the  apex  into  a  tendril-like  prolongation,  which  has 
apparently  been  very  generally  considered  as  the  entire  leaf. 
The  various  stages  of  growth  were  traced,  and  in  the  mature  leaf 
of  the  fully  developed  plant  this  small  blade  still  remains  in  size 
and  outline  the  same  as  in  the  young  plantlet. 
That  this  flattened  portion  of  the  leaf  was  really  the  blade  of  a 
sessile  leaf,  and  not  a  winged  petiole  or  a  phyllode,  was  evidenced,, 
as  it  was  flattened  with  the  faces  to  the  earth  and  sky,  and  not  the 
edges,  and  the  apex  continues  in  growth  without  articulation  or 
twisting.  The  venation  likewise  indicates  that  it  is  a  lamina.  This 
observation  would  seem  to  be  an  additional  confirmation  of  the 
more  modern  classification  of  the  Sundews,  as  Sarraceniales  with 
Sarraceniaceae  and  Nepenthaceae,  and  the  leaf  character  of  this 
plant  would  indicate  a  near  relationship  to  Nepenthes. 
In  the  Sarracenia  the  enlarged  petiole  is  really  a  phyllode,  being 
flattened  and  hollowed  out,  forming  the  pitcher,  and  the  lamina  is 
reduced  to  the  small  lid-like  projection  at  the  apex  of  the  leaf.  In 
Nepenthes  the  flattened  blade  is  present,  and  the  apex  of  the  leaf 
develops  into  a  long  tendril,  on  the  termination  of  which  is  formed 
the  cup  or  pitcher.  In  Drosera  filiformis  the  small,  flattened  blade 
is  present,  and  the  apex  is  developed  into  a  filiform,  tendril-like 
elongation,  but  no  cup  is  formed. 
