40 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
have succeeded in passing. This is indicated by the fact that a much 
larger proportional number of Arid Transition plants have fomud 
their way from California into the Columbia Basin, as hereafter 
shown. 
There is a third element, however, in the make-up of the Upper 
Sonoran flora of Washington, namely, those species which seem to 
have originated in the Columbia Basin, or at least are not known 
elsewhere. 
SPECIES PECULIAR TO THE COLUMBIA BASIN. 
Abronia mellifera. Lomatium geyeri. 
Antennaria flagellaris. ; Oreocarya celosioides. 
Arabis whitedii. Oreocarya spiculifera. 
Arenaria franklinii. Pentstemon glandulosus, 
Claytonia arenicola. Pentstemon pruinosus. 
Conanthus parviflorus. Phaca collina. 
Eragrostis lutescens. Phaca diphysa. 
Brigeron curvifolius. Pheca lyallii. 
Brigeron filifotius. Phaca misella. 
Erigeron linearis. Phaca reventa, 
Hrigeron poliospermus., Phaca sclerocarpa. 
Briogonum niveum. Phaca sinuata. 
Hriogonum proliferum, Phaca speirocarpa. 
Erysimum occidentale, Phacelia lenta. 
Gilia leptomeria. Pteryxia terebinthina. 
Helianthus cusickii. Talinum spinescens. 
Lappula arida. Thelypodium streptanthoides, 
Lappula ciliata. Tonella floribunda, 
Leptotaenia purpurea. Tounsendia florifer. 
Leptotaenia salmoniflora. Trifolium megacephalum. 
Lesquerella douglasii. Viola trinervata. 
HUMID TRANSITION AREA. 
The Pacific coast region west of the Cascade Mountains in British 
Columbia, Washington, Oregon, and northwestern California, is 
notable for its moist climate and equable temperature no less than 
for the very luxuriant forests which these conditions foster. This 
region has sometimes been referred to as the Northwest Coast Strip, 
an unfortunate name, as the term “ Northwest ” has been used in too 
many senses to give it accuracy. Adopting a suggestion of Mr. D. A. 
Brodie, the term Vancouver Strip is here given to the region, for 
which it is desirable to have a definite name in conformity with the 
remarkably uniform flora and fauna which it possesses. The name 
above suggested commemorates the name of the navigator who first 
thoroughly explored the region and whose name has there been 
attached to the largest island and to two important towns. 
Much the greater portion of the Vancouver Strip belongs to the 
Pacific or Humid Transition area. The most characteristic tree is 
