﻿PLANTS 
  OF 
  CHINA 
  — 
  WALKER 
  359 
  

  

  have 
  lived 
  to 
  see 
  fruitful 
  fields 
  in 
  their 
  homeland 
  bearing 
  valuable 
  

   crops 
  as 
  a 
  result 
  of 
  their 
  hard 
  labors 
  in 
  distant 
  China. 
  

  

  The 
  plant-disease 
  aspects 
  of 
  plant 
  introduction 
  are 
  very 
  important 
  

   and 
  interesting. 
  In 
  1913 
  after 
  the 
  chestnut-bark 
  disease, 
  then 
  of 
  

   unknown 
  origin, 
  had 
  begun 
  its 
  devastating 
  attack 
  on 
  this 
  highly 
  

   important 
  forest 
  tree 
  in 
  America, 
  Frank 
  N. 
  Meyer, 
  well-known 
  United 
  

   States 
  Department 
  of 
  Agriculture 
  explorer 
  (pi. 
  11, 
  fig. 
  1), 
  discovered 
  

   the 
  same 
  disease 
  in 
  China. 
  He 
  also 
  found 
  that 
  the 
  Chinese 
  chestnut 
  

   trees 
  were 
  able 
  to 
  survive 
  the 
  attacks 
  of 
  this 
  disease, 
  suffering 
  only 
  

   wounds 
  from 
  which 
  they 
  could 
  recover 
  (pi. 
  10, 
  fig. 
  2). 
  The 
  evidence 
  

   is 
  strong 
  that 
  by 
  some 
  unknown 
  means 
  this 
  disease 
  of 
  the 
  inner 
  bark, 
  

   caused 
  by 
  a 
  fungus 
  called 
  Endothia 
  parasitica, 
  found 
  its 
  way 
  into 
  

   this 
  country 
  where 
  our 
  trees 
  were 
  not 
  immune. 
  To 
  replace 
  our 
  

   doomed 
  chestnuts 
  the 
  United 
  States 
  Department 
  of 
  Agriculture 
  has 
  

   obtained 
  large 
  quantities 
  of 
  seed 
  from 
  selected 
  Chinese 
  trees 
  which 
  

   have 
  survived 
  the 
  disease 
  and 
  are 
  therefore 
  known 
  to 
  be 
  immune. 
  

   Hence, 
  in 
  the 
  course 
  of 
  time, 
  we 
  will 
  have 
  new 
  chestnut 
  trees 
  for 
  shade 
  

   and 
  chestnut 
  bark 
  for 
  tannin. 
  

  

  Another 
  aspect 
  of 
  the 
  plant-disease 
  problem 
  is 
  the 
  introduction 
  

   from 
  China 
  of 
  insecticide 
  plants. 
  A 
  few 
  years 
  ago 
  the 
  casual 
  dis- 
  

   covery 
  of 
  an 
  article 
  published 
  in 
  Chinese 
  in 
  a 
  current 
  entomological 
  

   periodical 
  from 
  Chekiang 
  Province 
  revealed 
  the 
  use 
  there 
  of 
  an 
  in- 
  

   secticide 
  powder 
  prepared 
  from 
  the 
  roots 
  of 
  Tripterygiwm 
  wilfordii, 
  

   a 
  shrub 
  of 
  the 
  staff-tree 
  family 
  (Celastraceae). 
  This 
  organic 
  poison, 
  

   long 
  known 
  in 
  China, 
  is 
  far 
  superior 
  to 
  mineral 
  poisons, 
  such 
  as 
  those 
  

   prepared 
  with 
  arsenic, 
  because 
  it 
  disintegrates 
  and 
  becomes 
  harmless 
  

   by 
  the 
  time 
  vegetables 
  and 
  fruits 
  sprayed 
  with 
  it 
  are 
  ready 
  to 
  be 
  

   eaten. 
  Plants 
  of 
  this 
  species 
  were 
  obtained 
  by 
  the 
  United 
  States 
  

   Department 
  of 
  Agriculture 
  through 
  consular 
  officers 
  and 
  Chinese 
  

   plantsmen 
  for 
  experimental 
  cultivation 
  and 
  investigation 
  in 
  this 
  

   country. 
  Great 
  benefits 
  are 
  likely 
  to 
  result 
  from 
  this 
  introduction 
  

   when 
  the 
  details 
  of 
  its 
  growth 
  and 
  preparation 
  have 
  been 
  perfected. 
  

  

  Many 
  other 
  examples 
  might 
  be 
  given 
  of 
  various 
  benefits 
  to 
  this 
  

   country 
  resulting 
  from 
  plant 
  introduction. 
  In 
  like 
  manner 
  China 
  is 
  

   destined 
  to 
  benefit 
  from 
  importations 
  from 
  the 
  United 
  States 
  and 
  

   other 
  temperate 
  regions. 
  As 
  yet 
  little 
  attention 
  has 
  been 
  given 
  in 
  

   China 
  to 
  this 
  method 
  of 
  helping 
  to 
  solve 
  her 
  food 
  problems, 
  but 
  be- 
  

   ginnings 
  have 
  been 
  made 
  in 
  extending 
  the 
  work 
  on 
  a 
  scientific 
  basis. 
  

   In 
  certain 
  parts 
  of 
  China, 
  as 
  for 
  example 
  the 
  higher 
  parts 
  of 
  Kansu 
  

   Province, 
  it 
  would 
  be 
  possible 
  to 
  grow 
  more 
  nutritive 
  plants 
  than 
  are 
  

   now 
  commonly 
  cultivated, 
  if 
  the 
  right 
  varieties 
  adapted 
  to 
  their 
  par- 
  

   ticular 
  climates 
  and 
  soils 
  could 
  be 
  found. 
  Eeference 
  has 
  previously 
  

   been 
  made 
  to 
  the 
  introduction 
  of 
  foreign 
  trees 
  for 
  planting 
  in 
  inter- 
  

  

  