﻿58 
  INTRODUCTION 
  TO 
  BOTANY 
  

  

  of 
  cork 
  which 
  form 
  outside 
  the 
  green 
  bark. 
  Photosynthetic 
  

   work 
  is 
  also 
  done 
  by 
  the 
  stems 
  of 
  most 
  common 
  annual 
  plants 
  

   of 
  the 
  farm 
  and 
  garden, 
  such 
  as 
  corn, 
  beans, 
  peas, 
  and 
  potatoes. 
  

  

  FIG. 
  39. 
  Twigs 
  of 
  coffee 
  tree, 
  showing 
  how 
  leaves 
  are 
  supported 
  so 
  as 
  to 
  

   give 
  them 
  complete 
  exposure 
  to 
  light 
  

  

  57. 
  The 
  stem 
  raises 
  leaves 
  into 
  the 
  light. 
  Competition 
  for 
  

   light 
  is 
  extremely 
  common 
  among 
  plants. 
  One 
  of 
  the 
  main 
  

   reasons 
  why 
  the 
  surface 
  of 
  the 
  earth 
  in 
  a 
  very 
  dense 
  forest 
  

   - 
  the 
  forest 
  floor, 
  as 
  it 
  is 
  called 
  - 
  - 
  is 
  comparatively 
  bare 
  of 
  

   flowering 
  plants 
  is 
  that 
  they 
  cannot 
  get 
  enough 
  light 
  there 
  

   to 
  live. 
  In 
  a 
  cornfield 
  it 
  often 
  seems 
  as 
  if 
  the 
  weeds 
  were 
  

  

  