﻿MAY 
  4, 
  1922 
  proceedings: 
  botanical 
  society 
  237 
  

  

  many 
  other 
  kinds; 
  in 
  some 
  cases 
  with 
  double 
  or 
  multiple 
  whorls 
  of 
  ray- 
  

   flowers 
  about 
  the 
  disk, 
  or 
  with 
  the 
  florets 
  closely 
  crowded 
  into 
  compact 
  

   pompons 
  or 
  bunches 
  (Manipuli). 
  The 
  roots 
  he 
  described 
  as 
  fleshy 
  and 
  

   succulent, 
  and 
  clustered 
  like 
  those 
  of 
  the 
  classic 
  asphodel. 
  This 
  description, 
  

   although 
  written 
  about 
  1576, 
  was 
  first 
  published 
  in 
  the 
  Madrid 
  edition 
  of 
  

   his 
  works 
  in 
  1750. 
  In 
  the 
  Roman 
  edition 
  of 
  1790, 
  however, 
  are 
  figured 
  three 
  

   forms 
  of 
  Dahlia, 
  all 
  of 
  them 
  with 
  multiple 
  florets 
  suggesting 
  forms 
  now 
  called 
  

   the 
  peony 
  type, 
  but 
  differing 
  in 
  their 
  foliage, 
  the 
  first 
  two 
  having 
  leaves 
  

   like 
  those 
  commonlv 
  called 
  Dahlia 
  variabilis, 
  the 
  last 
  with 
  divided 
  leaves 
  

   like 
  those 
  of 
  Dahlia 
  glahraia, 
  or 
  D. 
  gracilis. 
  

  

  Four 
  years 
  later 
  in 
  addition 
  to 
  Dahlia 
  pinnata, 
  Cavanilles 
  described 
  and 
  

   figured 
  two 
  other 
  species. 
  Dahlia 
  coccinea 
  and 
  Dahlia 
  rosea, 
  "single 
  flowered" 
  

   forms 
  differing 
  from 
  each 
  other 
  not 
  only 
  in 
  color 
  but 
  also 
  in 
  the 
  form 
  and 
  

   texture 
  of 
  the 
  leaves. 
  Some 
  writers 
  declare 
  that 
  these 
  were 
  merely 
  two 
  va- 
  

   rieties 
  of 
  the 
  same 
  species, 
  while 
  others 
  deny 
  the 
  possibility 
  of 
  this, 
  declaring 
  

   that 
  D. 
  coccinea 
  and 
  D. 
  rosea 
  cannot 
  even 
  be 
  cross-pollinated 
  to 
  form 
  hybrids. 
  

  

  The 
  great 
  revolution 
  in 
  Dahlia 
  culture 
  which 
  led 
  to 
  the 
  creation 
  of 
  the 
  

   beautiful 
  forms 
  of 
  today 
  was 
  brought 
  about 
  by 
  the 
  importation 
  of 
  Dahlia 
  

   juarezii 
  into 
  Europe 
  about 
  the 
  year 
  1864, 
  a 
  type 
  of 
  which 
  is 
  here 
  presented, 
  

   accompanied 
  by 
  a 
  photograph 
  of 
  the 
  well-known 
  "Kalif" 
  of 
  our 
  gardens, 
  

   which 
  seems 
  to 
  be 
  a 
  facsimile 
  of 
  it. 
  Dahlia 
  juarezii 
  is 
  the 
  ancestor 
  of 
  all 
  our 
  

   cactus 
  dahlias. 
  It 
  is 
  interesting 
  to 
  note 
  that 
  the 
  type 
  of 
  this 
  species 
  like 
  

   that 
  of 
  Dahlia 
  pinnata, 
  was 
  a 
  "double 
  form" 
  and 
  in 
  all 
  probability 
  a 
  hybrid. 
  

   Recently, 
  Mr. 
  Wilson 
  Popenoe, 
  an 
  explorer 
  for 
  the 
  United 
  States 
  Depart- 
  

   ment 
  of 
  Agriculture, 
  came 
  upon 
  a 
  single 
  red 
  Dahlia 
  in 
  the 
  mountains 
  of 
  

   Guatemala 
  with 
  narrow 
  rays 
  reflexed 
  or 
  folded 
  backward 
  as 
  in 
  Dahlia 
  juarezii 
  

   and 
  its 
  descendents. 
  This 
  species, 
  which 
  I 
  named 
  Dahlia 
  popenovii 
  in 
  honor 
  

   of 
  its 
  collector, 
  is 
  in 
  all 
  probability 
  the 
  ancestor 
  which 
  gave 
  to 
  Dahlia 
  juarezii 
  

   and 
  to 
  all 
  the 
  cactus 
  dahlias 
  their 
  tendency 
  to 
  fold 
  back 
  the 
  margins 
  of 
  their 
  

   florets. 
  

  

  On 
  the 
  same 
  slide 
  is 
  shown 
  Dahlia 
  maxonii, 
  another 
  species 
  from 
  Guatemala, 
  

   collected 
  by 
  Mr. 
  William 
  R. 
  Maxon 
  in 
  the 
  Department 
  of 
  Alta 
  Verapaz 
  in 
  

   1905. 
  The 
  latter 
  species 
  was 
  for 
  a 
  time 
  confused 
  with 
  Dahlia 
  imperialis, 
  

   from 
  which 
  it 
  differs 
  radically 
  in 
  its 
  upright 
  instead 
  of 
  pendent 
  flowers, 
  as 
  

   well 
  as 
  in 
  the 
  form 
  of 
  its 
  leaves. 
  It 
  is 
  in 
  all 
  probability 
  an 
  ancestor 
  of 
  the 
  hy- 
  

   brid 
  Dahlia 
  excelsa, 
  the 
  type 
  of 
  which 
  was 
  a 
  cultivated 
  plant 
  with 
  abnormally 
  

   elongated 
  disk-flowers 
  resembling 
  the 
  so-called 
  anemone-flowered 
  types 
  of 
  

   our 
  gardens. 
  

  

  Concerning 
  the 
  roots 
  of 
  the 
  Dahlia, 
  these 
  were 
  compared 
  by 
  early 
  writers 
  

   with 
  those 
  of 
  the 
  asphodel, 
  which 
  were 
  also 
  fleshy 
  and 
  grew 
  in 
  clusters. 
  At- 
  

   tempts 
  have 
  been 
  made 
  to 
  use 
  the 
  roots 
  for 
  food 
  for 
  cattle 
  and 
  pigs, 
  but 
  on 
  

   account 
  of 
  the 
  unpleasant 
  taste 
  they 
  have 
  been 
  rejected. 
  Instead 
  of 
  starch 
  

   the 
  roots 
  contain 
  a 
  substance 
  known 
  chemically 
  as 
  inulin. 
  From 
  this 
  a 
  

   sugar 
  known 
  as 
  levulose 
  or 
  fructose 
  is 
  obtained. 
  This 
  sugar 
  is 
  sixty 
  per 
  cent 
  

   sweeter 
  than 
  cane 
  sugar, 
  but 
  it 
  has 
  hitherto 
  commanded 
  such 
  very 
  high 
  prices 
  

   that 
  it 
  has 
  not 
  been 
  of 
  commerical 
  importance. 
  It 
  crystallizes 
  with 
  great 
  

   difficulty, 
  and 
  the 
  expense 
  has 
  been 
  chiefly 
  due 
  to 
  the 
  fact 
  that 
  it 
  was 
  neces- 
  

   sary 
  to 
  use 
  much 
  alcohol 
  in 
  eliminating 
  the 
  water. 
  Although 
  this 
  sugar 
  

   crystallizes 
  with 
  difficulty, 
  yet 
  it 
  can 
  be 
  utilized 
  even 
  in 
  the 
  form 
  of 
  syrup, 
  

   especially 
  at 
  soda 
  fountains, 
  and 
  as 
  an 
  ingredient 
  for 
  various 
  drinks 
  and 
  des- 
  

   serts. 
  

  

  