354 RYDBERG: PHYTOGEOGRAPHICAL NOTES 
Mvcranthes aestivalis — Euphrasia mollis 
Spathularia Brunnoniana Valeriana sitchensis 
ferruginea tCampanula heterodoxa 
Argentina subarctica Erigeron grandiflorum 
{|Hedysarum Mackenzii Erigeron lanatus 
Moneses reticulata tAntennaria monocephala 
Androsace septentrionalis* tArtemisia Richardsontana 
tAmarella propinqua Petasites frigida 
}Dasystephana glauca a corymbosa 
+ Castilleja 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 MounrtTaAINS 
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,t the Engelmann spruce, Picea Engelmannt. 
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 oF 
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. 
Tt See Bull. Torrey Club 42: 11. Ja I9I5. 
