Northern Dominion District. 547 
the former mountains are more humid than the latter and because the snow 
fall is heavier, so that there are few plants in flower in early summer, but by 
July and August the mountain slopes, the borders of mountain brooks and 
the high meadows are bright with flowers. 
As the country included in this district has not been wholly explored and 
as large tracts are, therefore, geographically unknown, we are far from pos- 
sessing complete information about the flora. The following notes practically 
sum up in general way our knowledge of the vegetation of the district‘). 
Coniferous Forest Formation. This varies in different localities. The follow- 
ing trees enter into this formation in the Rocky Mountains: Pseudotsuga 
Douglas (= P. taxifola = P. mucronata), which‘ occurs on the eastern 
slopes of these mountains about the mouth of the Kananaskis and up the 
valley of the Bow River. In the dry southern portion of the interior it is 
confined to the higher uplands between the various river valleys. It is absent 
from the higher portions of the Selkirks. Northward, however, it comes down 
to the general level of the country. — The western hemlock 7suga Merten- 
siana (= T. heterophylla)”) occurs on the coast and follows up the Fraser 
and other rivers to the limit of abundant rainfall. It appears in the Selkirk 
and Gold ranges and is found on the west slopes of the Rockies, while 7suga 
Paltoniana (= T. Mertensiana) is an alpine species in the fastnesses of the 
Selkirks. — T7huja plwata (= T. gigantea), is unknown in the dry central 
plateau but is found in the damp valleys of the Selkirk and Gold Range 
mountains. — Picea Engelmanni is the prevailing forest tree of the Cana- 
dian Rocky Mountains (see plate I) and appears to characterize the interior 
plateau forming a dense stand on the mountains. Northeastward, where it 
mingles with Picea alba. (= P. canadensıs), its limits are indefinable. It borders 
the streams and swamps in the northern portion of British Columbia at 2,500 
to 3,500 feet altitude. — Adies subalpina (= A. lasiocarpa) grows abundantly 
in the Gold and Selkirk ranges and in the Rocky Mountains east of McLeod’s 
ı) The writer is indebted to the botanic explorations of Miss EDITH FArR, Mrs. CHARLES 
SCHÄFFER, Messrs. CHARLES H. Suaw, M. H. JacoBs, STEWARDSON BROWN, E. NEWTON HARvEY 
the late EpwArp R. HeAcocK of Philadelphia or information about the plants of the Cana- 
an Rockies and Selkirk mountains. See also, VAn BRUNT, CORNEL The wild Flowers of 
ce Canadian Rockies. Transactions ech, Horticultural rn 1898: Part I, 182; 
FARR, EDITH M.: Contributions to a Catalogue of the Flora of the Canadian Rocky Mountains 
and the Selkirk Range. Contrib. Bot. Lab. Univ. of Penna (1907) III: 1—88; et er and 
. Mrs. CHARLES SCHÄFFER: Alpine Flowers of the Canadian Rocky Mountains 1908; W 
A. O.: The Selkirk Range Vol. 1 text: Vol. II, maps Ottawa 1905, see especially the Basen 
pages 399 Se 
2) A mos Mr unforkunafe confusion of names is found in the synonymy of the two hemlocks 
of the western states. The western hemlock in be older systematice works is designated Tsuga 
Mertensiana Engelmann! {not Carriere), but other botanists call it Tsuga heterophylla (Raf.) Sarg. 
The mountain hemlock long designated Tsuga Pattoniana (A. .) Sen@lacuze, becomes Tsuga 
Mertensiana (Bong.) Carr. In order to prevent this confusion throughout this work, the two hem- 
locks are quoted thus: Western coast hemlock, Tsuga Mertensiana (=T. ee moun- 
tain hemlock, (Tsuga Pattoniana) (=T. Mertensiana). _ 
aB 
