THE FORESTS OF THE FLATHEAD VALLEY, MONTANA. 
CONTRIBUTIONS FROM THE HULL BOTANICAL LABORATORY. 
LXVII. 
; HARRY N. WHITFORD. 
(WITH MAP AND TWENTY-THREE FIGURES) 
[Concluded from p. 218] 
THE undergrowth of the Douglas spruce-bull pine combination is 
decidedly heath- or prairie-like. In the more open places grass is 
predominant, and associated with the grasses are Balsamorrhiza 
sagittata, Monarda scabra, Lupinus ornatus, and Clarkia pulchella. 
The most common bushes are Prunus demissa, Amelanchier alni- 
jolia, Opulaster pauciflorus, and Symphoricarpos sp. In places 
where the rock is near the surface a heath-like appearance is given 
to the undergrowth by the presence of Cladonia sp., Arctostaphylos 
Uva-ursi, Campanula rotundifolia, Selaginclla densa, Lepargyraea 
argentea, and Pteridium aquilinum; other forms noted were Galium 
- boreale, Achillea millejolium, Holodiscus ariaefolia, and Populus 
tremuloides; and along the pebbly shores of the lake Crataegus is 
very characteristic. 
On the southern slope of Swan Hill the vegetation conditions 
found on the exposed slopes of Mission Mountains are approximated, 
though this area is slightly more mesophytic; and the same may be 
said for the east side of Swan Lake. Here the shores end abruptly 
in a range of hills on whose west slope Douglas spruce and bull pine 
are characteristic, though here and there are scattered groups of 
western larch. Another meso-xerophytic area on the east side of 
Big Fork River, not far from the foot of the lake (map), has already 
been mentioned. 
The country lying to the south and southwest of Flathead Lake 
is semi-arid (fig. 5), but in favorable situations there is some woody 
vegetation. A fringe of trees around the borders of the lake yond 
tains principally Rocky Mountain juniper, hawthorn, and bull pine; 
and the same condition is found along Pend d’Oreille River where 
276 [sven 
