28 THE TRUCKEE AND HUMBOLDT VALLEYS. 
mountain top, as no portion of it is below four thousand feet. 
Notwithstanding the general sterility of the soil it will be 
seen, as I proceed, that it sustains quite an extensive and 
peculiar flora. With the belief that a brief sketch of this 
unique region will be of interest to naturalists I have ven- 
tured to present the results of my observations. 
My first botanical rambles were along the banks of the 
Truckee River, which has its source in Lake Tahoe, a lovely 
sheet of pure, cold and clear water, situated on the eastern 
boundary of California. From this Alpine lake the little 
river flows into the Great Basin and waters some of the best 
farming lands in Nevada. It is a narrow and rapid stream, 
mostly shallow, and with a rocky or sandy bottom. At 
intervals nature has adorned its banks with groves of cotton- 
wood (Populus monilifera). It is sincerely to be hoped that 
these noble trees will be spared by the rapacious wood-chop- 
pers, as in a country so meagre in its sylva, a green thing, 
if it be but a shrub, is cheering to the spirit, and a full-sized 
tree is a positive delight. The size of these poplars, and the. 
wide spread of their branches, render them especially wel- 
come to the traveller, who, parched and weary, seeks refuge 
within their shade. | 
In speaking of the plants of Nevada it is convenient to 
classify them much as they are distributed in nature, and we 
find that according to their location they naturally fall into 
three grand divisions : 
lst. The plants of the river bottoms and margins of irri- 
gating canals. 
2d. Those found on the desert plains at a distance from 
water. í 
3d. Those of the mountains. 
These main divisions for ease in study may again be sub- 
divided into sections almost as naturally marked, namely : 
A marginal section immediately contiguous to the rivers 
or lakes. 
A meadow tract, moistened generally by artificial irriga- 
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