Rydberg: Phytogeographical notes 



631 



part a number of species from the Montane Zone are added. 

 Along the water courses perhaps the most common grass in the 

 upper part is Deschampsia caespitosa. Where the soil is richer 

 the predominant grasses are Phleum alpinum, Agrostis variabilis, 

 Trisetum subspicatum, T. majus and several species of Poa. In 

 the lower part these, except the poas, are more or less replaced 

 by Alopecurus aristulatus, Muhlenbergia comata, Agrostis asperi- 

 folia, Graphephoriim muticum, and Danthofiia californica. Among 

 bushes, especially along the streams, the most common grasses 

 are Calamagrostis canadensis, C. Langsdorfii, Panicularia nervata, 

 and P. paiiciflora. In the Northern Rockies many wet meadows 

 are made up wholly of Alopecurus occidentalis, but this species is 

 rare in the Southern Rockies. 



The following grasses are found in the Subalpine Zone through- 

 out the whole Rocky Mountain region: 



*Muhlenbergia racemosa 



* " comata 

 *Phleum pratense 



alpinum 



* Alopecurus aristulatus 



occidentalis 



* Agrostis asperifolia 



" hyemalis 

 " variabilis 

 Calamagrostis Langsdorfii 

 canadensis 

 *Deschampsia atropurpurea 

 t " curtifolia 



caespitosa 



Trisetum subspicatum 

 " majus 

 *Graphephorum muticum 

 *Danthonia californica 



* ' ' intermedia 

 Poa pratensis 



" reflexa 

 leptocoma 

 alpina 



* " Olneyi 



* " Vaseyana 

 *Panicularia nervata 



paiiciflora 

 *Hordeum jubatum 



The following are restricted to one of the two divisions: 



Southern Rockies 



Poa callichroa 

 t " pudica 



occidentalis 

 * " tricholepis 



Northern Rockies 



Poa nervosa 



Muhlenbergia Wolfii 

 * Agrostis canina 

 ^Deschampsia alpicola 



Graphephorum Wolfii 



Agrostis variabilis 



