﻿246 
  KEY 
  AND 
  FLORA 
  

  

  at 
  the 
  apex 
  ; 
  chaff 
  as 
  long 
  as 
  the 
  flowers. 
  Akenes 
  oblong, 
  the 
  wings 
  

   narrow 
  and 
  thickened 
  ; 
  pappus 
  of 
  2 
  minute 
  teeth. 
  In 
  rich 
  woods.* 
  

  

  5. 
  C. 
  palmata 
  Nutt. 
  STIFF 
  TICKSEED. 
  Perennial; 
  stem 
  stiff, 
  

   smooth, 
  little 
  or 
  not 
  at 
  all 
  branched, 
  very 
  leafy, 
  1-3 
  ft. 
  high. 
  Leaves 
  

   3-cleft, 
  broadly 
  wedge-shaped, 
  stiff 
  ; 
  the 
  lobes 
  linear-oblong, 
  middle 
  

   one 
  often 
  3-lobed. 
  Heads 
  on 
  short 
  peduncles, 
  few 
  or 
  solitary, 
  1^-2 
  in. 
  

   in 
  diameter 
  ; 
  bracts 
  of 
  the 
  outer 
  series 
  narrower 
  than 
  the 
  inner 
  ones, 
  

   slightly 
  shorter. 
  Rays 
  6-10, 
  bright 
  yellow, 
  broad, 
  usually 
  3-toothed. 
  

   Akenes 
  oblong, 
  with 
  narrow 
  wings. 
  Dry 
  prairies 
  and 
  thickets 
  W. 
  

  

  6. 
  C. 
  verticillata 
  L. 
  Perennial 
  ; 
  stem 
  smooth, 
  stiff, 
  slender, 
  branch- 
  

   ing 
  freely, 
  leafy, 
  1-2 
  ft. 
  high. 
  Leaves 
  divided 
  into 
  3 
  sessile 
  leaflets, 
  

   the 
  latter 
  once 
  or 
  twice 
  pinnately 
  parted 
  into 
  narrowly 
  linear 
  or 
  thread- 
  

   like 
  divisions. 
  Heads 
  1^-1 
  1 
  in. 
  in 
  diameter; 
  outer 
  bracts 
  much 
  nar- 
  

   rower 
  than 
  the 
  inner 
  ones. 
  Rays 
  6-10, 
  yellow. 
  Akenes 
  oblong, 
  with 
  

   narrow 
  wings. 
  In 
  dry 
  or 
  moist 
  soil, 
  sometimes 
  cultivated. 
  

  

  VH. 
  HELENIUM 
  L. 
  

  

  Annual 
  or 
  perennial. 
  Leaves 
  alternate, 
  forming 
  wings 
  on 
  

   the 
  stem. 
  Pleads 
  radiate, 
  peduncled, 
  many-flowered; 
  bracts 
  in 
  

   2 
  series, 
  the 
  outer 
  linear 
  and 
  spreading, 
  the 
  inner 
  few 
  and 
  

   scale-like 
  ; 
  receptacle 
  naked, 
  convex 
  or 
  oblong. 
  Ray 
  flowers 
  pis- 
  

   tillate 
  and 
  fertile, 
  or 
  neutral, 
  the 
  rays 
  wedge-shaped, 
  3-5-lobed; 
  

   disk 
  flowers 
  bisexual, 
  tubular, 
  4-5-lobed. 
  Akenes 
  top-shaped, 
  

   hairy, 
  ribbed 
  ; 
  pappus 
  of 
  4^5 
  entire, 
  toothed 
  or 
  awned 
  scales.* 
  

  

  1. 
  H. 
  nudiflorum 
  Nutt. 
  SNEEZEWEED. 
  Perennial; 
  stem 
  slender, 
  

   erect, 
  downy, 
  branched 
  above, 
  1-2 
  ft. 
  high. 
  Leaves 
  lanceolate, 
  entire 
  

   or 
  slightly 
  toothed, 
  the 
  lower 
  petioled, 
  the 
  upper 
  sessile. 
  Heads 
  nu- 
  

   merous. 
  Ray 
  flowers 
  10-15, 
  neutral, 
  yellow 
  or 
  yellow 
  and 
  brown; 
  

   disk 
  flowers 
  purple. 
  Akenes 
  hairy 
  on 
  the 
  ribs 
  ; 
  pappus 
  of 
  ovate, 
  

   minutely 
  toothed, 
  awned 
  scales. 
  Common 
  on 
  river 
  banks 
  S.* 
  

  

  VHI. 
  ACHILLEA 
  L. 
  

  

  Perennial. 
  Leaves 
  alternate, 
  pinnately 
  divided. 
  Heads 
  with 
  

   ray 
  flowers 
  in 
  a 
  terminal 
  corymb 
  ; 
  involucral 
  bracts 
  imbricated 
  

   in 
  several 
  series, 
  the 
  outer 
  shorter 
  ; 
  receptacle 
  chaffy. 
  Ray 
  

   flowers 
  white 
  or 
  pink, 
  pistillate 
  and 
  fertile 
  ; 
  disk 
  flowers 
  bi- 
  

   sexual, 
  tubular, 
  5-lobed. 
  Akenes 
  oblong, 
  compressed, 
  slightly 
  

   margined 
  ; 
  pappus 
  none.* 
  

  

  1. 
  A. 
  Millefolium 
  L. 
  YARROW. 
  Stems 
  often 
  clustered, 
  erect 
  from 
  

   a 
  creeping 
  rootstock, 
  simple, 
  downy 
  or 
  woolly, 
  1-2 
  ft. 
  high. 
  Leaves 
  

  

  