40 



CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



have succeeded in passing. This is indicated by the fact that a much 

 larger proportional number o^ Arid Transition plants have foui^d 

 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. 



Ahronia mellifcra. 

 Antennaria ffagellaris. 

 Arabis whitedU. 

 Arcnaria frauJclinii. , 

 Cluytonia areuicoJa. 

 Conanthus parviflorus. 

 Era (frost is lutcsceiis. 

 Erifjrron curvifoUus. • 

 Erigeron filifoUns. 

 Erigcron linearis. 

 Erigeron poliospcrmus. 

 Eriogon um ni ve nni. 

 Eriogmi mn proliferum. 

 Erifsimum occidcntale. 

 Gilia Irptonteria. 

 Hclianthus cnsickn. 

 Lappula arida. 

 Lappula ciliata. 

 Leptotaenia purpurea. 

 Leptotaenia saimoniflora. 

 Lesqiierella douglasii. 



Lomatinm geycrl. 

 Oreocarya celosioides. 

 Oreocarya spicnlifcra. 

 Pentstemon gland ulosus. 

 Pcntittemon pruiiiosus. 

 Phaca coUina. 

 Phaca diphysa. 

 Phaca lyallii. 

 Phaca miseUa. 

 Phaca rcventa. 

 Phaca sclcrocarpa. 

 Phaca sinuata. 

 Phaca speirocarpa. 

 Phacclia lenta. 

 Pteryxia tereJiinthina. 

 Talin um spinescens. 

 Thelypodium strcptanthoidea. 

 Tonella florihunda. 

 Toumsendia florifer. 

 Trifolium megacephalum. 

 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 



