Southern Park Mountain District. 553 
ERe undergrowth in the northern belts of Pinus ponderosa is noted for the absence of 
Menziesia ferruginea and M. glabella while Juniperus scopulorum, Salix Nuttallii (= S. flavescens), 
Alnus ehombifolia, Cercocarpus ledifolius, Amelanchier alnifolia, Crataegus ren (C brevispina), 
Prunus emarginata, Rhamnus Purshiana, Acer glabrum, Ceanothus sanguineus, C. velut ar Cornus 
stolonifera occur in considerable frequency. In the Coeur d’Alene ieh he sparse under- 
growth consists: of Holoiiisten discolor, Ceanothus sanguineus, Philadelphus Lewisii we pr 
Carex Geyeri 
In the Bitterroot Mountains according to PAMMEL in this forest belt are found with Pinus 
ponderosa the following: Rubus Nutkanus, Prunus deals, Philadelphus microphyllus, Amel- 
anchier gs Betula occidentalis, Geranium Fremontii, Berberis repens (= B. aquifolium *), 
Th neipal species in this formation where Pinus ponderosa and Pinus flexilis are associated 
in the Pils Peak country in Colorado are in spring, Arctostaphylos uva-ursi, Pentstemon secundi- 
florus, P. humilis, and as secondary species occur Draba streptocarpa, Pentstemon humilis var. 
roseiflora, Erigeron multifidus. The summer growing plants are Geranium caespitosum, Potentilla 
fissa, Arenaria Fendleri and in autumn occurs Gentiana affınis. 
2. The Pinus monticola belt lies below 5,000 feet. It is predominant in 
many places. It is found especially between altitudes of 2,400 and 4,800 feet 
above sea level and reaches its greatest development between elevations of 
2,800 and 3,500 feet. The principal trees are Pinus monticola (42 per cent.), 
Larix occidentalis (35 per cent.), 7kuja plicata, Picea Engelmanni, western 
coast hemlock, 7suga Mertensiana, Abies grandis. Mixed with these species 
are scattered individuals of Pseudotsuga, Populus trichocarpa, Betula occidentalis, 
B. papyrifera, Salix Nuttallii, S. lasiandra. 
In northwestern Montana such a forest type occupies the middle slopes. The heaviest growth 
in this belt is on the level areas bordering the principal streams. Around Flathead Lake, Pinus 
monticola grows on lower Swan River and the South Fork of Flathead River together with Abies 
grande, Thuja plicata, western coast hemlock Tsuga Mertensiana, untain hemlock Tsuga 
Pattoniana. This belt of Pinus montieola oceupies northern and eastern a and follows canyon 
bottoms from an altitude of 5,90 feet down to 2,400 feet. 
The more common shrubs in the belt of Pinus monticola are Acer glabrum, Sambucus glauca, 
S. melanocarpa, Ceanothus sanguineus, C. velutinus, Cornus stolonifera, . Rhamnus hiana and 
Rubus parviflorus. ‘The upper areas toward the subalpine belt carry the densest undergrowth of 
over 80 per cent. of Menziesia ferruginea and M. glabella. 
3. The Abies subalpina-belt exists above 5,000 feet. It is not a 
continuous forest being broken at intervals by grassy slopes or rocky crests. 
In the main Adies subalpina and Pinus albicaulis prevail. The subalpine belt 
covers all the forested slopes in the Bitterroot Mountains having a northern, 
or direct western exposure above 5,800 feet. The forest trees in the main 
canyons in the Bitterroot ranges are Larix Lyallü, Abies subalpina (= A 
lasiocarpa), Pinus Murrayana, P. albicaulis, Abies grandis, Picea Be Hlennsens, 
Taxus brevifolia, mountain hemlock, 7suga Pattoniana. A great variety of 
combinations are formed by these trees, but the alpine fir is everywhere the 
predominating tree. In descending to 3,300 feet its associates are Pinus Mur- 
rayana, Picea Engelmanni. In the Yellowstone Park Adies subalpina is 
1) Pammer, L. H.: Notes on the sg: especially the forest Flora, of the Bitterroot Mount- 
ains. Iowa Academy of Science, 1905: S: 
