Puget Sound—Cascade District. 599 
Pseudotsuga Douglasii Belt. This type occupies areas situated at higher elevations 
than those of the yellow-pine type, hence these areas have considerably greater precipitation and 
soil humidity. On the western side of the Cascades it is the dominant type. It is never a pure 
type but Pinus ponderosa, P. Lambertiana, P. monticola, P. Murrayana, with an open undergrowth 
of Arctostaphylos nevadensis, Ribes cereum, Abies concolor, A. nobilis, coast hemlock Tsuga 
Mertensiana, Picea Engelmanni and Taxus brevifolia are mixed with it. Several types of this 
forest are recognizable where Abies concolor, or Pinus sus or Pinus Murrayana, or Pinus 
monticola, or Abies nobilis becomes the chief componen 
Tsuga Pattoniana Belt. The subalpine belt ach lies above 6,200 feet on the western 
slopes of the Cascade Mountains and 6,500 feet on the eastern is covered with forests of the 
alpine hemlock type. On small areas this forest is a pure growth of Tsuga Pattoniana (= T. 
Mertensiana) with an undergrowth of Vaceinium scoparium and V. membranaceum, elsewhere 
Pinus Murrayana, P. monticola, P. albicaulis, Abies nobilis, A. subalpina (A. lasiocarpa and Picea 
Engelmanni occur with Tsuga Pattoniana). The highest limits for the alpine-hemlock type are 
the timber lines, varying from 8,000 feet on northern slopes of the highest peaks to 9,500 feet 
on southern declivites. 
Along the edge of extreme timber line Tsuga Pattoniana is wanting and Pinus Beer 
reigns supreme. The following examples taken from the southern declivities of Mount in 
a are illustrative 2). 
imber line 800 feet below timber line: 
Pinus albicaulis ; ? 100 per cent | pinus albicaulis . . - sr per Fenk 
300 feet below timber ine: suga Pattoniana (= T. Mara: 
Ps anmeauls .„. . ....2.0.2...,5028 0% siana) . RE. 
Tsuga Pattoniana (= T. Merten- Abies Höhle. Se Bere Be JE 
Sana) Kae en > ee 
3. Prairie-, Meadow- and Alpine Formations. 
Gravelly Prairie Formation. Existing as islands in the red fir forests, 
which are unable to encroach because the gravelly prairie soil serves as an 
almost perfect barrier to this tree, are the prairies which present the appear- 
ance of. a sterile pasture with scattered oaks (Ouercus Garryana here and 
there). Until the middle of July these prairies are carpeted with flowers after 
which they assume an arid appearance. 
Sage Formation. This represents an extension of the Great Basin flora 
into the middle valley of the Fraser River in British Columbia. Where Jackass 
Mountain intercepts whatever little moisture comes up the valley of that river 
is an area where Artemisia tridentata becomes frequent. 
Associated with it are Artemisia frigida, Bigelovia (Chrysothamnus — Linosyris) graveolens, 
Plantago ee DM occidentalis, C. occidentalis var. nevadensis, Antennaria alpina, ki 
dimorpha, Myosurus aristatus, Phacelia eircinata (= P. heterophylla), P. Menziesii (= P. linearis 
Oxytropis campestris, Astragalus Beckwithii, A. pilifolia, Lithospermum pilosum, Chrysopsis hispida. 
and Amica foliosa?). 
Pumice Field Formation. About Crater Lake the gentle outer slopes con- 
sist of pulverized pumice without any admixture of humus. The vegetation 
1) LEIBERG, JoHn B.: Loc. cit. page 261. 
2) en Joun: Geologieal and Natural History Survey of Canada, a 
1875—76: 
