208 BOTANICAL GAZETTE [MARCH 
broad leaves of the maple, beech, and other deciduous trees. In 
places, however, considerable quantities of humus are present, espe- 
cially where the trunks of fallen trees have been allowed to decay 
and have not been destroyed by fire. A very good indication of a 
soil rich in humus is the number of species of fungi and mycotrophic 
seed plants found in it; Monotropa uniflora, Pterospora Andromeda, 
and Corallorhiza multiflora being scattered rather thickly throughout 
the forest. However, one misses the rich array of fleshy fungi found 
so abundantly in the leaf mold of the deciduous forests. Except in 
those places where arborvitae, hemlock, and lowland fir are prominent, 
the shade is not very dense; and under the rather thin canopy of the 
other conifers there is enough light to permit the development of a 
number of semi-shade species. 
A woody plant that gives a decided tone to the undergrowth 
throughout the mesophytic area and to some extent in the meso- 
xerophytic area is the dwarf maple (Acer glabrum), the only repre 
sentative of the maples found in Flathead valley. It can hardly be 
called a tree, for it seldom becomes more than 3™ in height. Other 
characteristic shrubby plants are Salix sp., Philadelphus Lewisti, 
Holodiscus ariaefolia, Amelanchier alnifolia, and Sym phoricar pos 
sp. In some places, usually more mesophytic, Mensiesta urceolaris 
and Taxus brevifolia are found. Some of the forms, like snowber'y, 
service berry, and mock orange, become more frequent as the forest 
becomes more open. Among the prominent more lowly forms were 
noted the following: Berberis aquifolium, Aralia nudicaults, Cornus 
canadensis, Chimaphila wmbellata, Pyrola rotundijolia, Linnaca 
borealis, Rubus parviflorus, Clintonia uniflora, Adenocaulon bicolor, 
Tiarella unijoliata, Lycopodium sp., and Disporum sp. 
At the south end of Swan Lake, on the west side of Big F 
River, is an area with a soil decidedly pebbly, and probably of glacial 
origin (map), its inability to hold water being indicated by the chat 
acter of the forest it supports. The Douglas spruce is about the only 
mesophytic tree found here, and in places there are groves of bull 
pine. On the east side of the river, so persistent is the absence ’ 
ork 
other species than Douglas spruce and bull pine, that the area W#* 
mapped as meso-xerophytic forest rather than mesophytc- ie 
rather open, and the vegetation in it becomes somewhat prairie- 
