﻿336 
  ANNUAL 
  REPORT 
  SMITHSONIAN 
  INSTITUTION, 
  1943 
  

  

  These 
  divisions 
  are 
  not 
  clearly 
  marked 
  off 
  from 
  each 
  other, 
  but 
  

   gradually 
  intergrade. 
  Of 
  course 
  it 
  must 
  not 
  be 
  supposed 
  that 
  the 
  

   vegetation 
  is 
  uniform 
  within 
  these 
  divisions; 
  it 
  actually 
  varies 
  con- 
  

   siderably 
  according 
  to 
  soil, 
  altitude, 
  and 
  climate. 
  Also 
  in 
  general 
  

   aspect 
  the 
  vegetation 
  in 
  most 
  parts 
  has 
  been 
  enormously 
  changed 
  by 
  

   man 
  from 
  that 
  which 
  unhindered 
  Nature 
  has 
  developed. 
  In 
  fact, 
  

   to 
  a 
  very 
  large 
  extent 
  we 
  can 
  only 
  determine 
  what 
  is 
  the 
  normal 
  

   vegetation 
  by 
  careful 
  study 
  of 
  the 
  few 
  remnants 
  which 
  man 
  has 
  not 
  

   yet 
  altered. 
  

  

  The 
  plants 
  that 
  compose 
  the 
  vegetation 
  of 
  these 
  regions 
  can 
  be 
  

   divided 
  according 
  to 
  their 
  geographic 
  affinities. 
  For 
  example, 
  the 
  

   banyan 
  trees 
  of 
  southern 
  China 
  occur 
  elsewhere 
  only 
  in 
  southern 
  

   Asia, 
  and 
  the 
  species 
  of 
  pines 
  found 
  in 
  Manchuria 
  occur 
  elsewhere 
  

   only 
  in 
  Siberia 
  and 
  northeastern 
  Asia. 
  Thus 
  the 
  plants 
  of 
  China 
  

   can 
  be 
  divided 
  into 
  the 
  following 
  eight 
  groups 
  based 
  on 
  their 
  geo- 
  

   graphic 
  affinities, 
  with 
  the 
  addition 
  of 
  a 
  ninth 
  group, 
  if 
  the 
  strictly 
  

   cultivated 
  plants 
  be 
  considered 
  as 
  part 
  of 
  the 
  flora 
  of 
  the 
  country. 
  

  

  1. 
  Palaearctic, 
  consisting 
  of 
  plants 
  which 
  occur 
  in 
  northern 
  Asia, 
  

   often 
  also 
  in 
  Europe 
  and 
  northern 
  North 
  America. 
  

  

  2. 
  Central 
  Asiatic, 
  occurring 
  in 
  Turkestan 
  and 
  vicinity, 
  usually 
  

   also 
  in 
  Asia 
  Minor 
  and 
  often 
  even 
  in 
  northern 
  Africa. 
  

  

  3. 
  Himalayan, 
  consisting 
  of 
  plants 
  found 
  in 
  the 
  temperate 
  and 
  

   alpine 
  parts 
  of 
  this 
  vast 
  range 
  south 
  of 
  Tibet. 
  

  

  4. 
  Indo-Malayan, 
  the 
  plants 
  which 
  are 
  found 
  exclusively 
  or 
  nearly 
  

   so 
  in 
  Indo-China, 
  the 
  Malay 
  Peninsula, 
  and 
  the 
  East 
  Indies. 
  

  

  5. 
  Insular 
  or 
  Japanese, 
  including 
  plants 
  extending 
  over 
  Hokkaido, 
  

   Japan 
  proper, 
  the 
  Liu 
  Kiu 
  Islands, 
  and 
  Formosa. 
  

  

  6. 
  North 
  American, 
  consisting 
  of 
  that 
  group 
  of 
  plants 
  found 
  in 
  

   eastern 
  Asia 
  and 
  eastern 
  North 
  America, 
  which 
  has 
  been 
  of 
  so 
  much 
  

   interest 
  to 
  plant 
  geographers. 
  

  

  7. 
  Cosmopolitan, 
  those 
  which 
  occur 
  so 
  widely 
  distributed 
  over 
  the 
  

   world 
  that 
  they 
  cannot 
  be 
  considered 
  as 
  indigenous 
  of 
  any 
  one 
  part. 
  

  

  8. 
  Endemics, 
  or 
  those 
  plants, 
  either 
  species, 
  genera, 
  or 
  even 
  fam- 
  

   ilies, 
  which 
  occur 
  nowhere 
  else. 
  

  

  The 
  following 
  discussion 
  is 
  mainly 
  concerned 
  with 
  the 
  floral 
  re- 
  

   gions, 
  because 
  considerable 
  knowledge 
  of 
  the 
  distribution 
  of 
  plants 
  

   is 
  needed 
  in 
  order 
  to 
  understand 
  floral 
  affinities. 
  However, 
  these 
  re- 
  

   lationships 
  will 
  be 
  considered 
  in 
  connection 
  with 
  each 
  region. 
  

  

  NORTHEASTERN 
  CHINA 
  

  

  This 
  floral 
  region 
  includes 
  Manchuria, 
  most 
  of 
  Korea, 
  the 
  great 
  

   plain 
  of 
  China 
  in 
  Shantung, 
  Shansi, 
  Chihli 
  or 
  Hopei, 
  and 
  most 
  of 
  Ho- 
  

   nan, 
  and 
  extends 
  south 
  over 
  northern 
  Anhwei 
  and 
  Kiangsu. 
  It 
  is 
  

   bounded 
  on 
  the 
  west 
  by 
  the 
  loess 
  deposits 
  of 
  Shansi 
  and 
  Shensi 
  and 
  

  

  