SOURCES OF THE VEGj!;TA.TiqN 



69 



^Taxus hrevifolia 

 ^Popuhis trichocarpa 

 *8alix fluviatilis ^ 



" melanopsis 



' ' exigua 



" argophylla 



" Mackemiaiia 



" vestita 



" sitchensis 



" Geyeriana 



" Scouleriatia 



" lella 



" glaucops 

 ^Rliamnus Purshiana 

 ^Echinopanax horridmn 

 ^Cornus NuttaUii 

 Ledum glandulosum 

 ^Fhododendron albiflorum 

 Phyllodoce empetriformis 

 " glandulif era 



Rosa nutkana 



" pyrifera 



' ' gymnocarpa 

 *Amelanchier alnifolia 

 ^Crataegus Douglasii 

 Sorbus scopiilina 

 *Prunus demissa 

 Prunus cmarginata 

 *Pachystivia Myrsinites 

 *Rhus Rydbergii. 

 CeanotJtus vehdinus 



" sanguineiia 



Kalmia microphylla 

 C'assiope Mertensiana 

 ^Gaultlieria humifusa 

 y accinium occidentale 

 * " membranaceum, 

 " oreopliilum 

 " scoparium 

 SympJi oricarpos vaccinioides 



*Mensiesia ferruginea 



The species listed above vary widely both as to their abun- 

 dance and as to the extent of their areal distribution. Some 

 (marked *) are found generally distributed throughout the re- 

 gion under discussion in their appropriate altitudes. Those 

 marked (*) are either rare or uncommon, confined to the lo- 

 calities or altitudes suited to their peculiar demands, which in 



'According to Belili (Bot. Gaz. 102-108. Ap. 1891), the group 

 Longifoliae, to which belong Salix flwviatilis, S. melanopsis, S. exigua, and 

 S. argophylla, "is distinctly American, clearly defined on every side, 

 shading off into no other by variation, hyliridizing with none. It is 

 not connected with the Old World forms by any synthetic type of the 

 present or of any preceding period, but apparently was derived from the 

 Me,\ican Plateau at the close of the Tertiary. In keeping with this 

 view i1 finds its fullest development and greatest variation in form and 

 structure on the Pacific Slope. Eastward it declines in vigor and 

 varialiility until on the Atlantic Coast it is of rare occurrence from 

 New Brunswick to the Potomac." Taking this view into account, there 

 is some doubt as to whether the species named should be regarded as 

 coming from the south or west. Considering, however, that 'the group 

 is most fully represented today in numbers and forms in western 

 Oregon and Washington, it seems most probable that they have come 

 into our region from that source and are so listed. 



