Puget Sound—Cascade District. 597 
Prunus demissa Walp. 
Rosa gymnocarpa Nutt. 
» Nutkana Presl. 
» californica Cham. et Schlecht. 
Spiraea Douglasii Hook. 
> (Holodiscus) discolor Pursh. 
> corymbosa Raf. 
Sorbus (Pirus) sambucifolia Cham. et 
chlecht. 
Pyrus (Malus) rivularis Dougl. 
Amelanchier alnifolia Nutt. 
Rubus nutkanus Moc. (= 
florus Nutt.). 
> spectabilis Pursh. 
>»  leucodermis Dougl. 
>» ursinus Cham. et Schlecht. 
»  pedatus Smith. 
»  lasiococcus A. Gray. 
Purshia (Kunzia) tridentata DC. 
Neillia (Opulaster) opulifolia L. 
Philadelphus Lewisii Pursh. 
R. parvi- 
Crataegus macracantha Lindl. (North ! 
of Rainier). 
Ribes sanguineum Pursh. 
»  bracteosum Dougl. 
»  viscösissimum Pursh. 
cereum Dougl. 
»  ciliosum Howell, 
lacustre var. molle A. Gray. 
divaricatum Dougl. 
Fatsia (Echinopanax) horrida B. et H. 
“ 
v 
Cornus canadensis L. 
»  Nuttallü Aud. 
» pubescens Nutt. (= C. occi- 
dentalis T. et G.) 
Sambucus melanocarpa A. Gray. 
> racemosa Linn. 
> glauca Nutt. 
Viburnum pauciflorum Pylaie. 
Symphoricarpus racemosus Michx. 
Lonicera ciliosa Poir. 
> involucrata Banks. 
Vaccinium parvifolium Smith (= V. 
myrtilloides A. Gray var. 
membranaceum Dougl. 
» myrtilloides Hook. 
» myrtillus L. var. 
phyllum Hook. 
ee tomentosa Dougl. 
nevadenss A. Gray 
(North of Rainier). 
Gaultheria ovatifolia A. Gray. 
Kalmia glauca Ait. (= M. urceolaria 
alisb.). 
Menziesia ferruginea Smith (= 
ceolaria Salisb.). 
Rhododendron albiflorum Hook. 
(= Azaleastrum albiflorum Hook.). 
Here too occur several whitish or 
reddish saprophytes: Monotropa 
hypopitys, Pterospora andromedea 
and Corallorhiza Mertensiana. 
micro- 
M. ur- 
The forest on the Cascade Mountains of southern Oregon, north of 
the Klamath Gap, which is a barrier of great antiquity and effectiveness in 
the distribution of plants‘), is overwhelmingly coniferous. This is especially 
the case east of the Cascades, where broad-leaved species of trees form but 
a fraction of one per cent of the forest stands, and where two conifers, Pinus 
ponderosa and P. Murrayana together constitute 88 per cent. West of the 
Cascades broad-leaved trees occur more plentifully, forming about 6 per 
cent of the entire forest; and while among the conifers two species Pinus 
ponderosa and Pseudotsuga particularly predominate, there is also a wider range 
of ratios among the balance than is found on the eastern side of the range. 
ı) See ante page 256. 
