40 



CONTKIBUTIONS 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 fouiid 

 their way from California into the Columbia Basin, as hereafter 

 shown. 



There is a third element, however, in the make-up of the Upp'?r 

 Sonoran flora of Washington, namely, those species which seem to 

 have originated in the Columbia Basin, or at least are not known 

 elsewhere. 



SPECIES PECXIIJAR TO THE COT.UMBIA RASIN. 



Ahrovia mcUifcra. 

 A n ten n o ria pngcUarift. 

 Arahifi whiteiln. 

 Arcn aria fraiikUnn. 

 Clapton id (rrriiicnla. 

 Con a)) til II K parriftorus. 

 Krai/rost is I iitcscen s. 

 I'jfii/rrDn ciirvifolius. 

 Erif/rmn plifolins. 

 Eri!/r)(j)i Jiiirarift. 

 Erii/cnni poliospcrni i(s. 

 Erio!/(>)iinn nirriini. 

 Eriof/oninii j)ntjifrrinii. 

 Eri/si)n II ni occidoifalr. 

 GiJia Irptouicria. 

 HrVia II til IIS CHSicJcii. 

 Lappiila nriiJa. 

 Lnppiila, ciliata. 

 Lcptoturn ia purpurea. 

 Leptotaenia salmon iff ora. 

 LesqiicreJla doiiglasii. 



Lomatiiiin r/ej/eri. 

 Oreoearya eelosioides. 

 Oreocarya spiciilifcra. 

 Pentstenioii i/landiilosus. 

 Pentsteiiioii priiiiiosiis. 

 Phaca eoUinii. 

 Phaca dipliysa. 

 Phaca lyallii. 

 Phaca iiiisella. 

 Phaca re vent a. 

 Phaca sclerocarpa. 

 J'liaea sinuata. 

 Phaca, speirocarpa. 

 ■ Phacelia lent a. 

 Ptery.ria terehinthina. 

 Taliiiinii sjtinescens. 

 TlieJypodiiiin streptantlioides. 

 Toiiella florihinida. 

 Toirnsendia ftorifer. 

 Trifoli II III ni cf/acephalum. 

 Viola trinerrata. 



HUMID TRANSITION AREA. 



The Pacific coast region west of the Cascade Mountains in British 

 Columbia, Washington, Oregon, and northwestern California, is 

 notal)le 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 witli tlie 

 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 im2:>ortant towns. 



Much the greater j^ortion of th(> Vancouver Strip belongs to the 

 Pacific or Humid Transition area. The most characteristic tree is 



