to the more moist forests along the north banks of all the broader 
streams. It also occupies the western slopes of the massive mountains 
in the northeast. Along the borders of the grassland, in limited areag 
this type forms typical park-like stands. Reproduction of its own kind 
is the common understory and is frequently dense. In mixed stands the 
most common associate is lodgepole pine, Pinus contorta, which is slow- 
ly crowded out. Inasmuch as the pure stands are limited in area and 
are commonly contiguous to stands dominated by Douglas fir, Pseudotsuga 
16 
Ps 
taxifolia, the associated shrubs are commonly those of the Douglas fir 
type, such as Physocarpus pauciflorus, Holodiscus discolor, Ceanothus 
sanguineus, and C. velutinus, Philadelphus Lewisii, Symphoricarpus al- 
bus, Prunus virginiana var. demissa and Spiraea corymbosa. The nine- 
bark, Physocarpus pauciflorus, is perhaps the most abundant, although 
in arid flats where lodgepole pine is abundant, Ceanothus velutinus is 
dominant. Herbs commonly associated are Pent stemon ovatus, P. atten- 
vatus, Thalictrum occidentale, Galium triflorum, Synthyris rubra, Eryth- 
ronium grandiflorum (flowering in early spring), Pteridium aquilinun, 
Smilacina racemosa, Drymocallis convallaria and Sieversia ciliata. 
DOUGLAS FIR-LARCH TYPE 
Merging with the yeliow pine, particularly on low hills and usvally oc- 
cupying thin-soiled slopes with southern exposure, is an association 
dominated by bouglas rir, Pseudotsuga taxifolia, commonly with larch. 
Larix occidentalis. In ovr region it rarely is found in extensive 
lands and then chiefly in the valley ot the Clark Fork west of Lake 
