1 8 BOTANY. 



BOTANY OF THE DES CHUTES BASIN. 



The botany of this area has the general characters of that of Rlamath basin, except that, as 

 we descend towards the Columbia, the forest of yellow pine gives place to scattered trees of the 

 western cedar, which are, in time, succeeded by a growth of bunch grass, covering the country 

 as exclusively as does the wild oat the vallejs of California. Near the Columbia, the streams 

 are bordered by Quercus garryana, which does not, however, here attain the size of the same 

 species in the valleys of the Willamette and Umpqua. 



BOTANY OF THE CASCADE MOUNTAINS. 



As has been mentioned, the general features of the botany of the Cascade mountains is 

 similar to that] of the Sierra Nevada of California, the greater portion of the species which 

 compose it extending southward as far as San Francisco. There are, however, many species, 

 both of trees and minor plants, which, quite local in their range, yet in certain districts repre 

 sented by great numbers of individuals, give a peculiar character to the prevalent vegetation. 

 There are other plants, which, common in the vicinity of the Columbia, do not extend south 

 ward below the California line. Of these the western larch, (Larix occidentalis,) and Abies 

 JVilliamsonii may be taken as examples. 



LOCAL BOTANY. 



In the vicinity of the Three Sisters we several times crossed and recrossed the main crest of 

 the Cascade mountains, and were able to study, very carefully, the different belts of vegetation 

 visible on the mountain sides, from the snow line down to the Des Chutes basin, on the east, 

 and to the Willamette valley on the west. At this point, the plain bordering the Des Chutes, 

 having an altitude of about 4,000 feet, is covered with a continuous forest of yellow pine. 



Along the streams coming down from the mountains are a few trees of the western larch, 

 nowhere in this vicinity found at a much greater elevation than the plateau I have mentioned. 

 With the larch are occasionally mingled Populustremuloides, P. monilifera, and P. angustifolia. 

 A few hundred feet up the mountain side the yellow pine is joined by the sugar pine and Pinus 

 contorta, the western balsam fir, and Douglas spruce, all of which combine to form a thick 

 forest. With these also are occasionally seen few and small trees of the western Arbor vitce, 

 (T. gigantca,*) and the large-leaved maple, (Acer macrophyllum.) A little higher we found Pinus 

 monticola of Douglas, to me scarcely distinguishable from the white pine of the eastern States, 

 and the silver fir, (Picea amabilis.} At the height of 6,000 feet the trees which I have 

 mentioned had all given place to Abies Williamsonii and Pinus cembroides, which rise to the line 

 of perpetual snow. As we descended toward the west these two species were again succeeded 

 by those I have mentioned as occurring on the eastern slope, but mingled in different numerical 

 proportions, the most abundant species, and those constituting the great mass of the forest, 

 being the Douglas spruce, the balsam fir, and the western Arbor vitce. Here we found, for the 

 first time, the Nootka cypress, which was confined to the western slope of the mountains. The 

 under shrubs of the forest, on the western slope, consisted of the chinquapin (Castanea cliryso- 

 phylla,*) Rhododendron, two species, Arctostaphylos tomentosa, and Spircea aricefolia, the ground 

 being covered with Berberis, &quot;Salal,&quot; and ferns, as in the forests of the coast mountains, to 

 which that of the western slope is like in all essential particulars. On the alpine summits of 



