﻿OCT. 
  19, 
  1922 
  Bi^AKE: 
  new 
  species 
  of 
  letterwood 
  395 
  

  

  resented 
  in 
  the 
  National 
  Herbarium. 
  The 
  following 
  key 
  based 
  chiefly 
  

  

  on 
  the 
  leaves 
  will 
  serve 
  to 
  separate 
  the 
  species. 
  

  

  Leaves 
  finely 
  appressed-puberulous 
  beneath. 
  

  

  Leaves 
  rather 
  densely 
  appressed-puberulous 
  beneath; 
  peduncles 
  solitary, 
  

   erect. 
  

   Petioles 
  2 
  to 
  5 
  mm. 
  long; 
  peduncles 
  (in 
  flower 
  and 
  fruit) 
  3 
  to 
  8 
  mm. 
  

   long; 
  receptacle 
  in 
  flower 
  3.5 
  to 
  7 
  mm. 
  wide. 
  

  

  1. 
  P. 
  guianensis. 
  

   Petioles 
  5 
  to 
  7 
  mm. 
  long; 
  peduncles 
  (in 
  flower 
  and 
  fruit) 
  10 
  to 
  15 
  mm. 
  

   long; 
  receptacle 
  in 
  flower 
  1 
  cm. 
  wide 
  or 
  more. 
  

  

  2. 
  P. 
  panamensis 
  . 
  

   Leaves 
  very 
  sparsely 
  appressed-puberulous 
  beneath 
  chiefly 
  along 
  the 
  

   costa; 
  peduncles 
  usually 
  paired, 
  refracted. 
  3. 
  P. 
  rubescens. 
  

  

  Leaves 
  densely 
  puberulous 
  to 
  pilosulous 
  beneath 
  with 
  spreading 
  or 
  in- 
  

   curved 
  but 
  not 
  appressed 
  hairs. 
  

   Leaves 
  gradually 
  long-acuminate, 
  puberulous 
  beneath 
  with 
  incurved 
  

   hairs; 
  chief 
  lateral 
  veins 
  14 
  to 
  22 
  pairs. 
  4. 
  P. 
  acutifolta. 
  

  

  Leaves 
  emarginate 
  or 
  rounded 
  to 
  abruptly 
  short-acuminate, 
  hispidulous 
  

   or 
  pilosulous 
  beneath 
  with 
  straight 
  spreading 
  hairs; 
  chief 
  lateral 
  

   veins 
  8 
  to 
  12 
  pairs. 
  

   Leaf 
  blades 
  mostly 
  4 
  . 
  5 
  to 
  7 
  . 
  5 
  cm. 
  long, 
  2 
  to 
  4 
  cm. 
  wide, 
  hispidulous 
  

   along 
  costa 
  above, 
  very 
  densely 
  scabridulous-hispidulous 
  on 
  sur- 
  

   face 
  beneath 
  with 
  minute 
  hairs 
  much 
  shorter 
  than 
  the 
  thickness 
  of 
  

   the 
  leaf 
  tissue. 
  5. 
  P. 
  scabridtda. 
  

  

  Leaf 
  blades 
  mostly 
  7 
  to 
  12 
  cm. 
  long, 
  3 
  to 
  5.5 
  cm. 
  wide, 
  glabrous 
  above, 
  

   rather 
  densely 
  velvety-pilosulous 
  on 
  surface 
  beneath, 
  the 
  hairs 
  

   about 
  as 
  long 
  as 
  the 
  thickness 
  of 
  the 
  leaf 
  tissue. 
  6. 
  P. 
  velutina. 
  

   1. 
  Piratinera 
  guianensis 
  Aubl. 
  PI. 
  Guian. 
  2: 
  888. 
  pi. 
  340. 
  1775. 
  Pale- 
  

  

  LEAE 
  LETTERWOOD. 
  Fig. 
  1, 
  a. 
  

  

  Brosimum 
  discolor 
  Schott 
  in 
  Spreng. 
  Syst. 
  Veg. 
  4^: 
  403. 
  1827. 
  

  

  Brosimum 
  guyanense 
  Huber, 
  Bol. 
  Mus. 
  Goeldi 
  5: 
  337. 
  1909. 
  

  

  Piratinera 
  discolor 
  Pittier, 
  Contr. 
  U. 
  S. 
  Nat. 
  Herb. 
  20: 
  100. 
  1918. 
  

   Type 
  locality 
  : 
  Caux, 
  French 
  Guiana. 
  

   Illustrations: 
  Aubl. 
  PI. 
  Guian. 
  pi. 
  J40. 
  Miq. 
  in 
  Mart. 
  Fl. 
  Bras. 
  4': 
  

  

  pi. 
  J 
  J 
  (as 
  B. 
  discolor). 
  

   Specimens 
  examined 
  : 
  

  

  British 
  Guiana: 
  Komentyne 
  (Komantin) 
  Creek, 
  Wiruni 
  River, 
  and 
  

   Berbice 
  River 
  (near 
  savanna 
  of 
  Karaka), 
  February 
  18, 
  1910, 
  C. 
  W. 
  An- 
  

   derson 
  467/C. 
  T. 
  45 
  (N, 
  Yale).* 
  Essequibo-Rupumuni 
  region, 
  Ander- 
  

   son 
  598 
  A 
  (N, 
  Yale). 
  On 
  hills 
  up 
  to 
  15 
  or 
  20 
  meters 
  above 
  sea 
  level, 
  

   Kamuni 
  Creek, 
  Demerara 
  River, 
  Anderson 
  137 
  (Yale). 
  Issororo 
  Creek, 
  

   Pomeroon 
  River, 
  June 
  8, 
  1909, 
  Anderson 
  308 
  (Yale). 
  

  

  Surinam: 
  Zandery 
  I., 
  a 
  station 
  at 
  Km. 
  45 
  of 
  railway, 
  November 
  25, 
  

   1915, 
  Forestry 
  Service 
  (Surinam) 
  1371 
  (Yale). 
  Moderzorg, 
  Surinam 
  

   River, 
  August 
  8, 
  1921, 
  Forestry 
  Service 
  5429 
  (Yale). 
  Sarwa 
  Creek, 
  

   Mapane, 
  Commewyne 
  River, 
  November 
  22, 
  1921, 
  Forestry 
  Service 
  

   5497 
  (Yale, 
  fragm. 
  N). 
  Berlyn, 
  Km. 
  50 
  of 
  railway, 
  December 
  13, 
  

   1921, 
  Forestry 
  Service 
  5501 
  (Yale, 
  fragm. 
  N). 
  

  

  Brazil: 
  Obidos, 
  Amazonia, 
  December 
  22, 
  1907, 
  Ducke 
  9189 
  (N). 
  

  

  * 
  In 
  the 
  citation 
  of 
  specimens, 
  N 
  = 
  U. 
  S. 
  National 
  Herbarium; 
  Yale 
  = 
  herbarium 
  of 
  

   Yale 
  University. 
  

  

  