﻿196 
  KEY 
  AND 
  FLORA 
  

  

  I. 
  ASCLEPIODORA 
  Gray. 
  

  

  Plants 
  much 
  like 
  Asclepias, 
  but 
  the 
  hoods 
  without 
  horn& 
  

   Lobes 
  of 
  the 
  corolla 
  ascending 
  or 
  spreading. 
  

  

  1. 
  A. 
  viridis 
  Gray. 
  GREEN 
  MILKWEED. 
  Stems 
  about 
  1 
  ft. 
  high, 
  

   nearly 
  smooth. 
  Leaves 
  alternate, 
  short-petioled, 
  oblong 
  to 
  ovate- 
  

   lanceolate. 
  Umbels 
  clustered. 
  Flowers 
  about 
  1 
  in. 
  in 
  diameter, 
  

   green 
  -with 
  a 
  purplish 
  crown. 
  In 
  dry 
  soil 
  W. 
  and 
  S. 
  

  

  H. 
  ASCLEPIAS 
  L. 
  

  

  Perennial 
  herbs. 
  Flowers 
  in 
  simple 
  (usually 
  many-flowered) 
  

   umbels. 
  Calyx 
  small, 
  5-parted, 
  its 
  lobes 
  reflexed. 
  Corolla 
  deeply 
  

   5-parted, 
  with 
  reflexed 
  lobes 
  ; 
  crown 
  of 
  hoods 
  and 
  horns 
  con- 
  

   spicuous 
  (Fig. 
  27, 
  A, 
  ). 
  Stamens 
  with 
  their 
  filaments 
  united 
  

   into 
  a 
  tube 
  around 
  the 
  pistil 
  and 
  anthers 
  attached 
  to 
  the 
  stigma 
  

   (Fig. 
  27, 
  D, 
  E) 
  ; 
  anther 
  cells 
  2, 
  each 
  cell 
  containing 
  an 
  elon- 
  

   gated, 
  pear-shaped, 
  tough 
  mass 
  of 
  pollen, 
  a 
  mass 
  from 
  one 
  

   anther 
  always 
  paired 
  with 
  one 
  from 
  the 
  adjoining 
  anther 
  and 
  

   each 
  two 
  together 
  suspended 
  from 
  one 
  of 
  the 
  5 
  split 
  glands 
  

   on 
  the 
  angles 
  of 
  the 
  stigma 
  (Fig. 
  27, 
  D, 
  E). 
  Ovaries 
  2 
  ; 
  styles 
  

   very 
  short. 
  Pods 
  2 
  or 
  sometimes 
  1 
  and 
  the 
  other 
  undeveloped. 
  

   Seeds 
  flat, 
  each 
  with 
  a 
  tuft 
  of 
  long, 
  silky 
  hairs. 
  The 
  flowers 
  

   are 
  pollinated 
  by 
  insects, 
  which 
  get 
  their 
  feet 
  entangled 
  in 
  

   the 
  clefts 
  of 
  the 
  glands 
  (Fig. 
  27, 
  g) 
  and 
  then 
  carry 
  off 
  the 
  

   pollen 
  masses. 
  

  

  1. 
  A. 
  tuberosa 
  L. 
  BUTTERFLY 
  WEED, 
  PLEURISY 
  ROOT. 
  Stems 
  

   roughish-hairy, 
  1-2 
  ft. 
  high. 
  Juice 
  not 
  milky. 
  Leaves 
  abundant, 
  

   linear 
  to 
  lanceolate-oblong. 
  Flowers 
  showy, 
  usually 
  bright 
  orange, 
  

   in 
  terminal 
  cymose 
  umbels. 
  Horns 
  nearly 
  erect 
  and 
  slender. 
  Pods 
  

   nearly 
  erect, 
  covered 
  with 
  fine 
  down. 
  In 
  dry 
  fields. 
  

  

  2. 
  A. 
  decumbens 
  L. 
  RECLINING 
  BUTTERFLY 
  WEED. 
  Much 
  resem- 
  

   bling 
  A. 
  tuberosa, 
  but 
  the 
  stems 
  rrrlining 
  with 
  the 
  ends 
  erect. 
  Leaves 
  

   elliptic 
  or 
  oblong. 
  Umbels 
  racemed 
  along 
  the 
  branches. 
  In 
  dry 
  soil. 
  

  

  3. 
  A. 
  purpurascens 
  L. 
  PURPLE 
  MILKWEED. 
  Stem 
  1-3 
  ft. 
  high, 
  

   somewhat 
  branched 
  above. 
  Leaves 
  4-6 
  in. 
  long, 
  elliptical 
  or 
  nearly 
  

   so, 
  the 
  upper 
  ones 
  taper-pointed, 
  slightly 
  velvety 
  beneath, 
  short- 
  

   petioled. 
  Umbels 
  terminal. 
  Flowers 
  J 
  in. 
  long, 
  dark 
  purple 
  ; 
  pedi- 
  

   cels 
  shorter 
  than 
  the 
  peduncle 
  ; 
  horn 
  broadly 
  scythe-shaped, 
  with 
  the 
  

   point 
  bent 
  sharply 
  inward. 
  Dry 
  soil. 
  

  

  