236 Dr James Hector on the Physical Features of the 
mountain torrents along with a matting of Dryas and Epi- 
lobium, and other alpine plants, the seeds of which are washed 
down every spring. 
On descending the mountains as far as the Kootani River, 
which flows south-east for eighty miles through a wide valley 
lying parallel with-the direction of the chain, a marked 
change is again observed in the nature of the vegetation. 
The forest is free from undergrowth, and consists principally 
of the Pinus ponderosa, which in its habit much resembles 
the Scotch fir, and frequently reaches the size of four feet in 
diameter. Along with it is the Larix occidentalis, which is 
equal in girth, but exceeds the pine in height and symmetry. 
Amongst the noble forest which these trees form, a rider can 
gallop with ease in every direction, the only underbrush consist- 
ing of a few scattered bushes of the red root (Ceanothus) or of 
the Shepherdia argentea. On the alluvial flats by the river, 
the Juniperus virginiana was found as far north as 51° 30’ to 
occur as a large tree 25 feet in height and 1 foot in diameter, 
The surface of the ground, where dry and gravelly, is 
covered with wiry tufts of “ bunch grass,” and the slopes are 
clothed with a shrubbery of cherry and service-berry bushes 
(Amelanchier), the fruit of which is the principal food of the 
Kootani Indians. Westward from the Kootani River to Fort 
Colville, upon the Columbia, the country is very rugged, and 
when not confined in narrow valleys the forest generally 
forms open pine glades. By the sides of the streams and the low 
borders of lakes the yew and arbutus are found to occur, and 
in favourable spots the Thuja gigantea acquires an enormous 
size—often ten or twelve feet indiameter. Nevertheless, the 
prevailing physiognomy of the vegetation in this district is of 
the arid type; and further to the south, in the Columbian 
desert, this character is found to reach an extreme phase, 
there being a total absence of timber; and the country, even — 
where the surface is irregular and rocky, supports nothing 
but a growth of dry tufty grass, or the worthless sage bush. 
(Artemisia tridentifolia). This sterility increases as we ap- 
proach the Cascade Range; but on passing these mountains by 
the narrow chasm through which the Columbian River escapes 
to the Pacific, the change in the character of the vegetation 
