﻿A 
  FLORA 
  OF 
  ARKANSAS 
  TERRITORY. 
  159 
  

  

  HYDROCHARIDEAE. 
  

  

  Vallisneria 
  spiralis 
  (V. 
  Americana, 
  Willd.). 
  

   Udora 
  Canadensis. 
  

  

  *PONTEDEREAE. 
  

  

  Schollera 
  graminifolia. 
  In 
  ponds 
  near 
  the 
  banks 
  of 
  the 
  Arkan- 
  

   sas 
  ; 
  rare. 
  

  

  Heteranthera 
  limosa. 
  

  

  Pontederia 
  cordata. 
  — 
  Rare. 
  

  

  Obs. 
  These 
  three 
  genera, 
  inseparable 
  in 
  natural 
  affinity, 
  appear 
  to 
  

   form 
  a 
  distinct 
  section, 
  better 
  referable 
  to 
  this 
  order 
  than 
  any 
  other 
  

   with 
  which 
  I 
  am 
  acquainted. 
  

  

  *ALISMOIDEAE. 
  

  

  1. 
  Alisma 
  plantago. 
  

  

  2. 
  A. 
  *roslrata. 
  Foliis 
  cordatis 
  obtusis 
  ; 
  scapo 
  subsimplici, 
  pauci- 
  

   floro 
  ; 
  capsulis 
  ovatis, 
  rostratis. 
  — 
  Hab. 
  In 
  the 
  ponds 
  of 
  the 
  Verdigris 
  

   river 
  of 
  Arkansas. 
  Flowering 
  in 
  June 
  and 
  July. 
  — 
  Obs. 
  The 
  plant 
  

   much 
  smaller 
  than 
  A. 
  plantago, 
  twelve 
  to 
  sixteen 
  inches 
  high; 
  the 
  

   scape 
  triquetrous, 
  frequently 
  simple, 
  or 
  with 
  at 
  most 
  two 
  or 
  three 
  

   branches 
  at 
  the 
  base, 
  as 
  in 
  the 
  inflorescence 
  of 
  Sagittaria 
  ; 
  the 
  leaves 
  

   5 
  to 
  7-nerved; 
  peduncles 
  three 
  together, 
  more 
  than 
  an 
  inch 
  in 
  

   length; 
  bracts 
  linear; 
  stamina 
  about 
  nine; 
  rostrum 
  of 
  the 
  fruit 
  almost 
  

   its 
  length. 
  Nearly 
  allied, 
  apparently, 
  to 
  A. 
  cordifolia 
  of 
  South 
  Ame- 
  

   rica. 
  

  

  1. 
  Sagittaria 
  sagittifolia. 
  2. 
  S. 
  graminea. 
  — 
  Obs. 
  The 
  leaves, 
  as 
  

   in 
  most 
  aquatics, 
  variable 
  in 
  form 
  and 
  magnitude, 
  in 
  place 
  of 
  linear 
  

   and 
  gramineous 
  often 
  long 
  and 
  lanceolate, 
  with 
  as 
  many 
  as 
  five 
  nerves 
  ; 
  

   The 
  peduncles 
  of 
  the 
  scape 
  are 
  all 
  remarkably 
  long 
  and 
  slender, 
  and 
  

   the 
  capitulum 
  of 
  fruit 
  smaller 
  than 
  usual. 
  

  

  3. 
  S. 
  *radicans. 
  Foliis 
  cordato-ovatis, 
  undulatis, 
  obtusis 
  ; 
  scapo 
  an- 
  

   gulato, 
  prostrato, 
  longissimo; 
  floribus 
  subverticillatis, 
  verticillis 
  radi- 
  

   cantibus. 
  — 
  Hab. 
  In 
  ponds 
  near 
  Fort 
  Smith. 
  Flowering 
  in 
  June 
  and 
  

   July. 
  — 
  Obs. 
  The 
  plant 
  rather 
  large, 
  with 
  the 
  petioles, 
  scape 
  and 
  calix 
  

  

  