﻿164 
  COLLECTIONS 
  TOWARDS 
  

  

  very 
  distinct 
  species 
  from 
  P. 
  aviculare, 
  and 
  a 
  much 
  larger 
  plant. 
  — 
  

   Common 
  to 
  many 
  parts 
  of 
  the 
  United 
  States 
  in 
  similar 
  situations. 
  

  

  3. 
  P. 
  tenue, 
  Mich. 
  Flor. 
  Am. 
  vol. 
  1, 
  p. 
  238; 
  Ph. 
  vol. 
  1, 
  p. 
  270. 
  

   4. 
  P. 
  hydropiperoides. 
  5. 
  P. 
  hirsutum. 
  6. 
  P. 
  Virginianum. 
  7 
  P. 
  

   articulatum. 
  8. 
  P 
  '. 
  parvifolium 
  (P. 
  polygamum, 
  Vent.). 
  — 
  On 
  the 
  sand 
  

   hills 
  of 
  Red 
  river. 
  9. 
  P. 
  convolvulus. 
  

  

  1. 
  Erio 
  Gomjm 
  *longifolium. 
  Caulescens; 
  foliis 
  oblongo-lanceolatis 
  

   striatis 
  suhtus 
  tomentosis, 
  caiilinis 
  solitariis 
  alternis; 
  ramis 
  floriferis 
  

   fastigiatis 
  corymbosis. 
  — 
  Hah. 
  On 
  the 
  ledges 
  of 
  the 
  Cadron 
  rocks, 
  and 
  

   in 
  denudated 
  prairies 
  from 
  Arkansas 
  to 
  Red 
  river. 
  — 
  Obs. 
  Root 
  partly 
  

   fusiform, 
  brownish 
  red, 
  astringent 
  and 
  bitter 
  to 
  the 
  taste, 
  in 
  some 
  

   measure 
  resembling 
  rhubarb 
  ; 
  leaves 
  cespitose, 
  a 
  span 
  long, 
  often 
  slightly 
  

   and 
  superficially 
  plaited, 
  above 
  villous 
  and 
  green, 
  beneath 
  white 
  and 
  

   tomentose; 
  stem 
  simple, 
  bearing 
  alternate 
  and 
  remote 
  leaves, 
  which 
  

   diminish 
  to 
  a 
  very 
  small 
  size 
  towards 
  the 
  summit 
  of 
  the 
  stem 
  ; 
  flower- 
  

   ing 
  branches 
  forming 
  a 
  compound 
  corymb. 
  Involucrum 
  cyathiform, 
  

   many-flowered 
  ; 
  pedicells 
  pilose 
  ; 
  flowers 
  whitish, 
  externally 
  tomentose 
  

   and 
  shining 
  ; 
  stamens 
  nine 
  ; 
  styles 
  three 
  ; 
  germ 
  lanuginous. 
  A 
  very 
  

   distinct 
  species, 
  allied 
  to 
  E. 
  tomentosum 
  of 
  Michaux. 
  

  

  2. 
  E. 
  *annuum. 
  Caulescens 
  ; 
  foliis 
  alternis 
  oblongo-lanceolatis 
  sub- 
  

   tus 
  tomentosis 
  ; 
  ramis 
  floriferis 
  nudis 
  cymosis 
  ; 
  floribus 
  glabris 
  dioicis. 
  

   — 
  Hab. 
  On 
  the 
  banks 
  of 
  the 
  Great 
  Salt 
  river 
  of 
  Arkansas, 
  and 
  near 
  

   the 
  confluence 
  of 
  the 
  Kiamesha 
  and 
  Red 
  rivers. 
  

  

  Descript. 
  Root 
  brownish, 
  perpendicular, 
  sending 
  out 
  few 
  fibres, 
  and 
  

   of 
  annual 
  duration 
  (all 
  the 
  other 
  species 
  of 
  the 
  genus 
  hitherto 
  dis- 
  

   covered 
  are 
  perennial) 
  ; 
  radical 
  leaves 
  crowded, 
  distantly 
  and 
  irregu- 
  

   larly 
  crenulate, 
  oblong 
  lanceolate 
  and 
  acute, 
  upper 
  surface 
  lanuginous, 
  

   the 
  under 
  white 
  and 
  tomentose 
  (after 
  the 
  manner 
  of 
  the 
  genus); 
  veins 
  

   transverse 
  and 
  branching 
  (in 
  the 
  preceding 
  species 
  longitudinal 
  and 
  

   parallel); 
  stem 
  terete 
  and 
  tomentose, 
  often 
  simple, 
  sometimes 
  consider- 
  

   ably 
  branched, 
  the 
  upper 
  part 
  naked, 
  the 
  lower 
  often 
  thickly 
  set 
  with 
  

   leaves, 
  destitute 
  of 
  nodes 
  or 
  swellings, 
  as 
  well 
  as 
  the 
  preceding, 
  the 
  

   stature 
  varying 
  from 
  one 
  to 
  three 
  feet; 
  cyme 
  compound; 
  involucres 
  

   and 
  flowers 
  cyathiform 
  ; 
  flowers 
  of 
  the 
  clusters 
  numerous, 
  whitish, 
  and, 
  

   as 
  in 
  no 
  other 
  species, 
  smooth 
  and 
  dioicous, 
  extremely 
  deciduous 
  ; 
  seg- 
  

   ments 
  of 
  the 
  petaloid 
  calix 
  unequal, 
  the 
  three 
  larger 
  in 
  the 
  styliferous 
  

  

  