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  52 
  

  

  INTRODUCTION 
  TO 
  BOTANY 
  

  

  saprophytes 
  have 
  fungi 
  growing 
  upon 
  their 
  roots 
  in 
  such 
  ways 
  

   as 
  to 
  assist 
  in 
  securing 
  food. 
  These 
  are 
  called 
  xi/ 
  ////>!<>(>' 
  x<i/,r<>- 
  

   phytes. 
  The 
  Indian 
  pipe 
  (Monoiropa) 
  often 
  has 
  these 
  root 
  

   fungi 
  ( 
  mycorrhiza). 
  

  

  I'urt'm! 
  saprophytes^ 
  among 
  flowering 
  plants, 
  are 
  not 
  easily 
  

   recognized 
  by 
  their 
  form 
  and 
  color, 
  bpt 
  may 
  he 
  known 
  by 
  their 
  

   inahility 
  to 
  flourish 
  without 
  considerable 
  humus 
  in 
  the 
  sml. 
  

  

  52. 
  Parasites. 
  The 
  dodders 
  are 
  the 
  most 
  familiar 
  flower- 
  

   ing 
  parasites. 
  One 
  of 
  the 
  commonest 
  species 
  is 
  abundant 
  

  

  in 
  the 
  central 
  and 
  north- 
  

   eastern 
  states, 
  its 
  thread- 
  

   like, 
  golden-yellow 
  stems 
  

   forming 
  great 
  tangled 
  

   masses 
  on 
  man}' 
  kinds 
  of 
  

   plants, 
  as 
  clover, 
  golden- 
  

   rods, 
  and 
  willows, 
  that 
  

   grow 
  in 
  damp 
  places. 
  

   The 
  dodders 
  (fig. 
  34) 
  and 
  

   some 
  root 
  parasites, 
  such 
  

   as 
  the 
  beechdrops, 
  squaw- 
  

   root, 
  and 
  cancer-root, 
  are 
  

   complete 
  parasites 
  and 
  have 
  

   no 
  green 
  foliage. 
  Other 
  

   plants, 
  such 
  as 
  the 
  mistle- 
  

   toe 
  (fig. 
  35), 
  have 
  green 
  leaves 
  and 
  do 
  photosynthetic 
  work, 
  

   but 
  depend 
  on 
  the 
  host 
  for 
  water 
  and 
  the 
  mineral 
  substances 
  

   dissolved 
  in 
  it. 
  Such 
  plants 
  are 
  called 
  jmrtnil 
  j>n/-nx/'f<-x. 
  

  

  53. 
  Damage 
  inflicted 
  by 
  parasites. 
  Many 
  parasites 
  take 
  so 
  

   much 
  water 
  and 
  plant 
  food 
  from 
  the 
  host 
  that 
  they 
  may 
  

   cause 
  serious 
  injury 
  to 
  cultivated 
  plants 
  and 
  to 
  forest 
  trees. 
  

   The 
  flax 
  dodder 
  and 
  the 
  clover 
  dodder 
  often 
  do 
  great 
  damage 
  

   to 
  crops 
  in 
  this 
  country 
  and 
  in 
  Europe, 
  and 
  another 
  species 
  1 
  

   is 
  sometimes 
  troublesome 
  in 
  fields 
  of 
  alfalfa. 
  In 
  the 
  south- 
  

   western 
  states 
  the 
  American 
  mist 
  let 
  oe 
  is 
  so 
  injurious 
  to 
  dicoty- 
  

   ledonous 
  trees 
  that 
  it 
  is 
  often 
  necessary 
  to 
  cut 
  it 
  away 
  from 
  

  

  1 
  Cuscitta 
  arveiisis. 
  

  

  ;. 
  35. 
  Mistletoe 
  growing 
  upon 
  a 
  branch 
  

  

  of 
  an 
  apple 
  tree 
  

   After 
  Bnniiier 
  and 
  Sablon 
  

  

  