﻿WATER 
  PLANTAIN 
  FAMILY 
  21 
  

  

  3. 
  ALISMACE.3. 
  WATER 
  PLANTAIN 
  FAMILY 
  

  

  Annual 
  or 
  perennial 
  marsh 
  herbs, 
  usually 
  with 
  creeping 
  run- 
  

   ners 
  or 
  rootstocks. 
  Stems 
  scape-like. 
  Leaves 
  long-petioled, 
  

   sheathing 
  at 
  the 
  base 
  ; 
  petiole 
  rounded 
  ; 
  blade 
  nerved, 
  netted, 
  

   or 
  sometimes 
  wanting. 
  Flowers 
  in 
  racemes 
  or 
  panicles, 
  bisex- 
  

   ual, 
  monoecious 
  or 
  dioecious 
  ; 
  pedicels 
  in 
  bracted 
  whorls. 
  Sepals 
  

   3, 
  persistent 
  ; 
  petals 
  3 
  or 
  wanting. 
  Stamens 
  6 
  or 
  more. 
  Ovaries 
  

   few 
  or 
  many, 
  1-celled, 
  1-seeded 
  ; 
  style 
  short 
  or 
  none. 
  Fruit 
  a 
  

   1-seeded 
  akene.* 
  

  

  I. 
  SAGITTARIA 
  L 
  

  

  Perennial 
  ; 
  rootstocks 
  mostly 
  knobby 
  or 
  tuber-bearing. 
  

   Scapes 
  erect 
  or 
  decumbent. 
  Leaves 
  long-petioled, 
  sheathing 
  

   at 
  the 
  base, 
  the 
  blade 
  round 
  and 
  netted, 
  or 
  wanting. 
  Flowers 
  

   monoecious 
  or 
  dioecious, 
  racemed 
  in 
  3-bracted 
  whorls 
  of 
  threes, 
  

   the 
  upper 
  flowers 
  usually 
  staminate. 
  Sepals 
  3, 
  persistent; 
  

   petals 
  3, 
  withering-persistent 
  or 
  deciduous. 
  Stamens 
  few 
  or 
  

   many. 
  Ovaries 
  in 
  globose 
  heads, 
  1-ovuled; 
  style 
  short, 
  per- 
  

   sistent. 
  Fruit 
  a 
  subglobose 
  head 
  of 
  flattened 
  akenes.* 
  

  

  1. 
  S. 
  latifolia 
  Willd. 
  BROAD-LEAVED 
  ARROWHEAD. 
  Leaves 
  very 
  

   variable 
  in 
  size 
  and 
  shape, 
  from 
  broadly 
  sagittate 
  to 
  linear, 
  those 
  

   growing 
  on 
  the 
  drier 
  soil 
  being 
  usually 
  the 
  broader 
  ; 
  petioles 
  6-30 
  

   in. 
  long. 
  Scape 
  smooth 
  or 
  slightly 
  downy, 
  6-36 
  in. 
  high 
  ; 
  bracts 
  

   acute. 
  Flowers 
  monoecious 
  or 
  sometimes 
  dioecious, 
  white, 
  1 
  in. 
  or 
  

   more 
  in 
  width 
  ; 
  pedicels 
  of 
  the 
  staminate 
  flowers 
  twice 
  the 
  length 
  of 
  

   those 
  of 
  the 
  fertile 
  flowers. 
  Filaments 
  long, 
  smooth, 
  and 
  slender. 
  

   Akenes 
  with 
  beak 
  nearly 
  horizontal. 
  Ditches 
  and 
  muddy 
  places.* 
  

  

  2. 
  S. 
  graminea 
  Michx. 
  GRASS-LEAVED 
  SAGITTARIA. 
  Leaves 
  

   long-petioled, 
  lanceolate, 
  or 
  elliptical, 
  and 
  acute 
  at 
  each 
  end, 
  3-5- 
  

   nerved, 
  or 
  often 
  linear, 
  the 
  earlier 
  often 
  reduced 
  to 
  flattened 
  petioles. 
  

   Scape 
  slender, 
  usually 
  longer 
  than 
  the 
  leaves, 
  simple, 
  weak, 
  often 
  

   prostrate 
  in 
  fruit; 
  bracts 
  small, 
  ovate, 
  connate 
  at 
  the 
  base. 
  Flowers 
  

   monoecious 
  or 
  dioecious, 
  on 
  long, 
  thread-like 
  pedicels, 
  about 
  ^ 
  in. 
  wide. 
  

   Stamens 
  10-20, 
  filaments 
  downy. 
  Akenes 
  nearly 
  beakless. 
  In 
  ditches 
  

   and 
  shallow 
  pools.* 
  

  

  H. 
  ALISMA 
  L. 
  

  

  Annual 
  or 
  perennial 
  herbs. 
  Leaves 
  erect 
  or 
  floating, 
  blades 
  

   prominently 
  ribbed 
  and 
  netted, 
  or 
  even 
  pinnately 
  veined. 
  

  

  