354 Rydberg: Phytogeographical notes 



Micranthes aestivalis Euphrasia mollis 



Spathularia Brunnoniana Valeriana sitchensis 



ferruginea ^Campanula heterodoxa 



Argentina subarctica Erigeron grandiflorum 



■\Hedysarum Mackenzi* Erigeron lanatus 



Moneses reticulata \Antennaria monocephala 



Androsace septentrionalis* \ Artemisia Richard soniana 



^Amarella propinqiia Petasites frigida 

 ^Dasy Stephana glauca " corymbosa 



■\CastiUeja pallida Senecio lugens 



6. Immigrants from the south 



Immigrants from the south are almost unknown in the Sub- 

 alpine Zone; they are more frequent in the Montane and Sub- 

 montane Zone and are very common in the Sonoran. The 

 following are the only ones found in the subalpine zone: 

 Pseudocymopterus purpureus Blepharineuron tricholepis 



III 



I. Endemic species, which also have emigrated into the 



Cascade Mountains 



The endemic element of the Rocky Mountains is by far the 

 largest. As the Rockies and the Cascades are connected through 

 several mountain chains it is natural that many of the endemic 

 Rocky Mountain species should have emigrated into the Cascade 

 Mountains. Let us treat these species first. 



The dominant tree in the Subalpine Zone is, as already stated 



in a previous article,! the Engelmann spruce, Picea Engelmannii. 



Often associated with it is found the subalpine fir, Abies lasiocarpa. 



Both extend throughout the Rockies from about latitude 55 degrees 



southward to the higher mountains of New Mexico and Arizona. 



They are also found in the northern portion of the western or 



Pacific province, i.e. throughout the Cascades, but not in the Sierra 



Nevada region. They are not found in the eastern province but are 



represented there by Picea canadensis, P. mariana, and Abies 



balsamea. Although the two species of Picea have been reported 

 — = — ^ 



* Also in Europe. 



t See Bull. Torrey Club 42: 11. Ja 1915. 



