58 
IOWA ACADEMY OF SCIENCE Vor,. XXVII, 1920 
It is of interest to note that some of the common European 
plants are naturalized at high altitude. Just below Berthoud pass, 
timothy (Phleum pratense) was common. The common lamb’s 
quarter (Chenopodium album) was found along the highway at 
an altitude of 10,000 feet near Berthoud and Milner pass. Pota- 
toes were growing at the ranger station, 9,000 feet, apparently 
not killed by the night freezing in early Angust. Peas in a garden 
at the ranger station produced a good crop. In early August lOr 
several nights white hoar frost covered the vegetation of the 
region, but it did not prevent the native plants in the region from 
blooming abundantly. 
CATALOGUE OF PLANTS 
In the following list the grasses were determined by Doctor 
A. S. Hitchcock, and the willows by Doctor C. R. Ball. The 
plants were collected by L. H. Pammel, D. C. Poshusta, Professor 
G. B. MacDonald and Professor G. C. Morbeck. 
PTERIDOPHYTES 
Polypodiaceae 
Woodsia oregana D. C. Eaton. Milner Pass, 11,700 feet; rocks; not 
common. 
Equisetaceae 
Bquisetum arvense L. West fork of St. Louis creek; Mount Byers; 
Grand river, 10,000 feet; common in moist places. 
Lycopodiaceae 
Lycopodium annotinum L. Beaver bog on west fork of St. Louis creek; 
not common. 
GYMNOSPERMS 
Pinaceae 
Pinus flexilis James. Below Berthoud Pass, 9,000 feet;. east slope of 
the Rockies near Empire. 
P. murrayana Balf. Timber line below 11,000 feet; Spruce creek; 
Mount Byers; Specimen Mountain. 
P. scopulorum Sarg. Golden, 8,500 feet; Empire. 
Picea Bngelmanni (Parry) Engelm. West fork of St. Louis* creek; 
Mount Byers, 10,000 feet; Grand river, 10,000 feet; Empire; Spruce creek, 
leaves three centimeters long. In swamps, canyons and slopes of moun- 
tains below timber line. 
P. pungens Engelm. Clear creek canyon. 
Abies lasiocarpa (Hook.) Nutt. Spruce creek; Mount Byers, 10,500 
feet; Specimen Mountain, 10,000 feet; Milner pass, 11,500 feet; Berthoud 
Pass, 8,500 feet. Slopes of mountains below timber line. 
Pseudotsuga taxifolia (Poir) Britton. Lookout Mountain, 8,500 feet; 
Empire; slopes of mountains. 
