﻿New 
  species 
  of 
  Uredineae 
  — 
  XII* 
  

  

  Joseph 
  Charles 
  Arthur 
  

  

  The 
  preceding 
  number 
  in 
  this 
  seriesf 
  was 
  issued 
  in 
  April, 
  

  

  m 
  

  

  1919. 
  Since 
  that 
  time 
  the 
  work 
  of 
  studying 
  and 
  assorting 
  all 
  of 
  

   the 
  remaining 
  material 
  in 
  the. 
  rust 
  herbarium, 
  not 
  heretofore 
  

   assigned 
  to 
  acceptable 
  genera 
  and 
  species, 
  has 
  proceeded 
  with 
  

   the 
  result 
  that 
  a 
  number 
  of 
  forms 
  have 
  been 
  separated 
  as 
  worthy 
  

   of 
  recognition 
  under 
  distinctive 
  names. 
  These 
  new 
  species, 
  

   founded 
  for 
  the 
  most 
  part 
  on 
  collections 
  that 
  have 
  long 
  reposed 
  

   In 
  various 
  herbaria, 
  together 
  with 
  two 
  species 
  that 
  have 
  been 
  

   passing 
  under 
  erroneous 
  names, 
  are 
  here 
  established. 
  A 
  few 
  

   species 
  are 
  transferred 
  to 
  other 
  genera, 
  and 
  in 
  three 
  cases 
  where 
  

   the 
  name 
  was 
  preoccupied 
  new 
  names 
  have 
  been 
  given. 
  

  

  Melampsora 
  americana 
  sp. 
  nov. 
  

  

  0. 
  Pycnia 
  hypophyllous, 
  scattered 
  among 
  the 
  aecla, 
  broadly 
  

   conic 
  or 
  hemispheric, 
  yellowish 
  or 
  light-brown, 
  rather 
  inconspi- 
  

   cuous, 
  subcuticular 
  but 
  extending 
  into 
  and 
  disintegrating^ 
  the 
  

   epidermal 
  cells 
  beneath, 
  80-150 
  /x 
  broad 
  by 
  50-90 
  m 
  high; 
  ostiolar 
  

  

  filaments 
  wanting. 
  

  

  1. 
  Aecia 
  hypophyllous, 
  scattered 
  over 
  part 
  or 
  all 
  of 
  the 
  leaf 
  on 
  

   yellowish 
  areas, 
  oval 
  or 
  oblong, 
  0.3-0.8 
  mm. 
  long, 
  soon 
  naked, 
  

   pulverulent, 
  at 
  first 
  orange-color, 
  becoming 
  pale-yellow, 
  ruptured 
  

   cuticle 
  barely 
  noticeable; 
  aeciospores 
  globoid 
  or 
  ellipsoid, 
  12-18 
  

   by 
  16-23 
  m; 
  wall 
  colorless, 
  1.5-2.5 
  fx 
  thick, 
  closely 
  and 
  finely 
  but 
  

  

  noticeably 
  verrucose. 
  

  

  II. 
  Uredinia 
  hypophyllous, 
  irregularly 
  scattered, 
  usually 
  on 
  

   yellow 
  spots, 
  round, 
  either 
  very 
  small, 
  0.1-0.2 
  mm. 
  across, 
  and 
  

   pale, 
  or 
  large, 
  0.2-0.5 
  "i^. 
  across, 
  pulvinate, 
  orange 
  fading 
  to 
  

   pale-yellow, 
  ruptured 
  epidermis 
  inconspicuous; 
  paraphyses 
  capi- 
  

  

  * 
  Reprints 
  may 
  be 
  obtained 
  by 
  application 
  to 
  the 
  Botanical 
  Department, 
  Purdue 
  

   University 
  Agricultural 
  Experiment 
  Station, 
  Lafayette, 
  Indiana, 
  under 
  whose 
  

   auspices 
  the 
  studies 
  here 
  reported 
  were 
  largely 
  carried 
  out. 
  

  

  t 
  New 
  species 
  of 
  Uredineae 
  I-XI: 
  Bull. 
  Torrey 
  Club 
  (I) 
  28: 
  661-666. 
  1901; 
  

  

  (II) 
  29: 
  227-231. 
  1902; 
  (III) 
  32: 
  1-8. 
  1904; 
  (IV) 
  33: 
  27-32. 
  1906; 
  (V) 
  33: 
  513- 
  

   522. 
  1906; 
  (yi) 
  34: 
  583-592. 
  1907; 
  (VII) 
  37: 
  569-580. 
  1910; 
  (VIII) 
  38: 
  369-378. 
  

  

  191 
  1 
  ; 
  (IX) 
  42:585-593. 
  1915; 
  (X) 
  45:141-156. 
  1918; 
  (XI) 
  46: 
  107-125. 
  1919. 
  

  

  465 
  

  

  