PIPER—-FLORA OF THE STATE OF WASHINGTON. 67 
THE COLUMBIA GORGE. 
The wonderful gorge of the Columbia River (Pl. XVIII), extend- 
ing a distance of about 50 kilometers (38 miles), presents peculiarities 
scarcely paralleled elsewhere in the Pacific northwest. The cliffs, ris- 
ing hundreds of meters vertically, present almost every rupestrine con- 
dition. Some of them are in almost perpetual shadow, others sub- 
jected to bright sunshine. Some become dry almost with the cessa- 
tion of the spring rains, others are bathed constantly in the spray of 
waterfalls. There are thus furnished suitable conditions, both to 
species from the arid interior and to others that normally flourish 
only in cool mountain valleys. The resultant association of Cana- 
dian or even Hudsonian species with those of the Transition zones is 
strikingly peculiar. 
That such an unusual environment should be the habitat of a con- 
siderable number of species not found elsewhere might have been 
predicted. No less than 16 species are practically confined to this 
region. They are: 
Agrostis howellii. Lomatium sp. nov. 
Calamagrostis howellii. Mimulus alsinoides. 
Delphinium trolliifoltium. Pentstemon barrettae. 
Dodecatheon dentatum. Poe imultnomae. 
Hrigeron howellii. Sullivantia oregana. 
Brigeron oreganus. Tellima odorata, 
Hemieva violacea. Valerianella aphanoptera. 
Hicracium longiberbe, Viburnum ellipticum. 
Some few others are worthy of special mention. Bolandra oregana, 
otherwise confined to the Columbia gorge, reappears on the bluffs of 
Snake River in Wallowa County, Oreg. 
Synthyris reniformis, abundant on the Oregon side of the gorge 
almost at the river’s edge, has its real home in the Canadian and Hud- 
sonian zones of the Blue and Bitterroot ,mountains. Like several 
other species, it does not occur on the Washington side of the Colum- 
bia gorge. 
A number of the Canadian and Hudsonian species that descend 
into the Columbia gorge are more or less modified from their original 
forms and may be regarded as subspecies, when compared with the 
alpine forms. Such are: 
Romanzoffia sitchensis, Saxifraga occidentalis. 
Saxifraga bronchialis. Valeriana sitchensis, 
Saxifraga caespitosa, 
But a larger number preserve their identity beyond question. Such 
are: 
Carex macrochacta, Pentstemon diffusus. 
Chelone nemorosa. Pentstemon rupicola. 
Cornus canadensis. Polypodium hesperium. 
Douglasia laevigata. Tofieldia intermedia. 
