﻿50 
  KEY 
  AND 
  FLORA 
  

  

  occasionally 
  escaped 
  from 
  cultivation 
  along 
  streams. 
  Very 
  variable 
  

   and 
  with 
  many 
  hybrids. 
  

  

  4. 
  S. 
  babylonica 
  L. 
  WEEPING 
  WILLOW. 
  A 
  spreading 
  tree, 
  some- 
  

   times 
  60 
  ft. 
  or 
  more 
  in 
  height, 
  with 
  drooping 
  branches. 
  Leaves 
  nar- 
  

   rowly 
  lanceolate, 
  taper-pointed, 
  serrate, 
  slightly 
  downy 
  when 
  young 
  

   and 
  becoming 
  smooth 
  with 
  age, 
  green 
  above, 
  pale 
  beneath, 
  often 
  5-7 
  

   in. 
  long; 
  petioles 
  short, 
  glandular. 
  Catkins 
  on 
  short 
  lateral 
  branches. 
  

   Stamens 
  2. 
  Style 
  almost 
  none. 
  Capsule 
  sessile, 
  smooth. 
  Introduced 
  

   and 
  cultivated 
  for 
  ornament. 
  

  

  5. 
  S. 
  cordata 
  JVluhl. 
  HEART-LEAVED 
  WILLOW. 
  A 
  shrub 
  4-10 
  ft. 
  

   high, 
  with 
  twigs 
  finely 
  downy 
  or 
  smooth. 
  Leaves 
  oblong-lanceolate, 
  

   taper-pointed, 
  finely 
  and 
  sharply 
  serrate, 
  often 
  tapering 
  but 
  frequently 
  

   obtuse 
  or 
  somewhat 
  heart-shaped 
  at 
  the 
  base, 
  finely 
  downy 
  when 
  

   young 
  (especially 
  on 
  the 
  midrib) 
  but 
  smooth 
  when 
  old 
  ; 
  sometimes 
  

   5 
  in. 
  long; 
  stipules 
  usually 
  large 
  and 
  conspicuous, 
  unequal-sided, 
  

   finely 
  serrate, 
  generally 
  persistent. 
  Catkins 
  with 
  bracts 
  at 
  the 
  base, 
  

   opening 
  earlier 
  than 
  the 
  leaves, 
  the 
  staminate 
  ones 
  very 
  silky, 
  less 
  

   than 
  1 
  in. 
  long, 
  the 
  fertile 
  ones 
  in 
  fruit 
  l-2 
  in. 
  long. 
  Capsules 
  nar- 
  

   rowly 
  ovoid, 
  pointed. 
  In 
  wet 
  soil 
  and 
  along 
  streams, 
  very 
  variable 
  

   and 
  widely 
  distributed. 
  

  

  6. 
  S. 
  discolor 
  Muhl. 
  GLAUCOUS 
  WILLOW, 
  PUSSY 
  WILLOW. 
  A 
  

   low 
  tree, 
  sometimes 
  20 
  ft. 
  or 
  more 
  in 
  height, 
  with 
  light 
  greenish- 
  

   brown 
  or 
  reddish-brown 
  bark. 
  Leaves 
  oblong-lanceolate, 
  tapering 
  at 
  

   both 
  ends, 
  finely 
  and 
  irregularly 
  toothed 
  or 
  nearly 
  entire, 
  on 
  slender 
  

   petioles, 
  smooth 
  and 
  firm, 
  bright 
  green 
  above, 
  smooth 
  or 
  silvery 
  

   white 
  below, 
  3-5 
  in. 
  long; 
  stipules 
  often 
  leaf-like, 
  unsymmetrical, 
  

   usually 
  deciduous. 
  Staminate 
  catkins 
  very 
  white 
  and 
  silky, 
  oblong- 
  

   cylindrical, 
  1 
  in. 
  or 
  more 
  long, 
  appearing 
  much 
  earlier 
  than 
  the 
  

   leaves; 
  pistillate 
  catkins 
  H-2 
  in. 
  or 
  more 
  long. 
  Stamens 
  2, 
  with 
  

   long, 
  slender 
  filaments. 
  Capsule 
  cylindrical 
  or 
  nearly 
  so, 
  long-beaked. 
  

   Common 
  in 
  wet 
  meadows 
  or 
  along 
  streams 
  and 
  swamps. 
  

  

  II. 
  POPULUS 
  L. 
  

  

  Trees 
  with 
  prominent 
  scaly 
  buds, 
  twigs 
  more 
  or 
  less 
  angled. 
  

   Leaves 
  usually 
  long-petioled. 
  

  

  Flowers 
  borne 
  in 
  long, 
  drooping 
  catkins, 
  which 
  appear 
  

   before 
  the 
  leaves 
  ; 
  scales 
  of 
  the 
  catkins 
  irregularly 
  cut 
  toward 
  

   the 
  tip. 
  Stamens 
  8-30 
  or 
  more. 
  Stigmas 
  2-4. 
  Capsules 
  open- 
  

   ing 
  early 
  by 
  2-4 
  valves. 
  

  

  1. 
  P. 
  alba 
  L. 
  SILVER-LEAVED 
  POPLAR, 
  WHITE 
  POPLAR. 
  A 
  large 
  

   tree, 
  sometimes 
  more 
  than 
  100 
  ft. 
  high, 
  with 
  smooth 
  greenish-gray 
  

   bark. 
  Leaves 
  broadly 
  ovate, 
  rhombic-oval 
  or 
  nearly 
  orbicular, 
  lobed 
  

  

  