﻿42 
  Elementary 
  Species 
  

  

  the 
  latter 
  part 
  of 
  the 
  summer 
  and 
  during 
  the 
  

   fall, 
  reaching 
  an 
  advanced 
  stage 
  of 
  development 
  

   of 
  the 
  branched 
  stems 
  before 
  winter. 
  Early 
  in 
  

   the 
  spring 
  the 
  flowers 
  begin 
  to 
  open, 
  but 
  after 
  

   the 
  ripening 
  of 
  the 
  seeds 
  the 
  whole 
  plant 
  dies. 
  

  

  The 
  three 
  perennial 
  species 
  just 
  mentioned 
  

   develop 
  in 
  the 
  same 
  manner 
  in 
  the 
  first 
  year. 
  

   During 
  their 
  flowering 
  period, 
  however, 
  and 
  

   afterwards, 
  they 
  produce 
  new 
  shoots 
  from 
  the 
  

   lower 
  parts 
  of 
  the 
  stem. 
  They 
  prefer 
  dry 
  and 
  

   sandy 
  soils, 
  often 
  becoming 
  covered 
  with 
  the 
  

   sand 
  that 
  is 
  blown 
  on 
  them 
  by 
  the 
  winds. 
  They 
  

   are 
  prepared 
  for 
  such 
  seemingly 
  adverse 
  cir- 
  

   cumstances 
  by 
  the 
  accumulation 
  of 
  food 
  in 
  the 
  

   older 
  stems 
  and 
  by 
  the 
  capacity 
  of 
  the 
  new 
  

   shoots 
  to 
  thrive 
  on 
  this 
  food 
  till 
  they 
  have 
  

   become 
  long 
  enough 
  to 
  reach 
  the 
  light. 
  F. 
  

   tricolor 
  ammotropha 
  is 
  native 
  near 
  Ystad 
  

   in 
  Sweden, 
  and 
  the 
  other 
  two 
  forms 
  on 
  Got- 
  

   land. 
  All 
  three 
  have 
  narrowly 
  limited 
  habi- 
  

   tats. 
  

  

  The 
  typical 
  tricolored 
  heartsease 
  has 
  re- 
  

   mained 
  annual 
  in 
  all 
  its 
  other 
  subspecies. 
  It 
  

   may 
  be 
  divided 
  into 
  two 
  types 
  in 
  the 
  first 
  place 
  : 
  

   F. 
  tricolor 
  genuina 
  and 
  F. 
  tricolor 
  versicolor. 
  

   Both 
  of 
  them 
  have 
  a 
  wide 
  distribution 
  and 
  seem 
  

   to 
  be 
  the 
  prototypes 
  from 
  which 
  the 
  rarer 
  forms 
  

   must 
  have 
  been 
  derived. 
  Among 
  these 
  latter 
  

   Wittrock 
  describes 
  seven 
  local 
  types, 
  which 
  

  

  