﻿Rydberg: 
  Phytogeographical 
  notes 
  

  

  447 
  

  

  Castilleja 
  confusa 
  

   Castilleja 
  rhexifoUa 
  

   Castilleja 
  trinervis 
  

  

  Pedicularis 
  Parryi 
  

   Pedicidaris 
  crenulata\ 
  

  

  Galium 
  jiaviflorum] 
  

  

  Oreochrystim 
  Parryi^. 
  

   Eucephaltis 
  wasatchensis\ 
  

   Eticephahis 
  glauciis\ 
  

  

  Eticephalus 
  formosus\ 
  

   Aster 
  adscendens 
  

  

  Erigeron 
  yellowstonensis 
  

   Erigeron 
  suhtrinervis 
  

   Afitennaria 
  viscidula 
  

   Anaphalis 
  subalpina 
  

   Helianthella 
  Parryi] 
  

   Arnica 
  macilenta\ 
  

  

  IV. 
  POPLAR 
  GROVES 
  , 
  

  

  These 
  are 
  found 
  in 
  the 
  narrower 
  valleys 
  and 
  canons, 
  where 
  

   there 
  is 
  a 
  certain 
  amount 
  of 
  moisture, 
  but 
  where 
  the 
  ground 
  Is 
  

   comparatively 
  well 
  drained- 
  The 
  principal 
  tree 
  is 
  the 
  narrow- 
  

  

  leaved 
  poplar 
  or 
  cottonwood, 
  Poptilus 
  

  

  ifolia 
  

  

  common 
  tree 
  is 
  Salix 
  Scouleriana, 
  and 
  Young* 
  has 
  called 
  this 
  for- 
  

  

  angustifolia 
  

  

  N 
  tit 
  t 
  aim 
  

  

  Another 
  common 
  tree 
  is 
  the 
  smooth 
  maple, 
  Acer 
  glahrum. 
  The 
  

   balsam 
  poplar, 
  Populus 
  balsamifera, 
  has 
  been 
  collected 
  in 
  a 
  few 
  

   places 
  in 
  Colorado, 
  and 
  the 
  canoe 
  birch, 
  Betnla 
  papyrijera 
  

   (B, 
  Andrewsii)j 
  has 
  been 
  collected 
  in 
  one 
  canon. 
  Some 
  of 
  the 
  

   evergreens 
  have 
  also 
  partly 
  invaded 
  this 
  formation, 
  as 
  Pseudotsuga 
  

   mucronata 
  and 
  Abies 
  concolor, 
  and 
  a 
  few 
  species 
  of 
  hawthorn 
  are 
  

   found 
  in 
  the 
  lower 
  part 
  of 
  the 
  zone. 
  In 
  the 
  Foothills 
  (Submontane 
  

   Zone) 
  the 
  narrow-leaved 
  cottonwood 
  is 
  replaced 
  mostly 
  by 
  

   Populus 
  acuminata 
  and 
  P. 
  Sargentii. 
  The 
  undershrub 
  and 
  

   herbaceous 
  vegetation 
  contains 
  many 
  species 
  found 
  in 
  the 
  Aspen 
  

   G 
  roves 
  - 
  

  

  I. 
  Trees 
  and 
  Shrubs 
  

  

  a. 
  Eastern 
  

  

  Populus 
  balsamifera 
  

   Salix 
  Bebhiana 
  

  

  Betiila 
  papyrijera 
  

   Dasiphora 
  fruticosa 
  

  

  b. 
  Western 
  

  

  Pseudotsuga 
  mucronata 
  

   Salix 
  Scouleriana 
  

   Ribes 
  viscosissimum 
  

  

  Cercocarpus 
  ledijolius 
  

   Rubacer 
  parviflorum 
  

   Riibus 
  melanolasius 
  

  

  ♦ 
  Bot- 
  Gaz. 
  44: 
  334-33<5. 
  IQO?- 
  

  

  