SOURCES OF THE VEGETATION 



69 



#Taxus brevifolia 

 ftPopulus trichocarpa 



*8alix fluviatilis 1 

 " melanopsis 

 " exigua 

 " argophylla 

 " Mackenzia^ia 

 " vestita 

 " sitchensis 

 " Geyeriana 

 " Scouleriana 

 " bella 

 " glaucops 



Rosa nutkana 



' ' pyrifera 



1 i gymnocarpa 

 *Amelanchier alnifolia 

 *Crataegus Douglasii 

 Sorbus scopulina 

 * Primus demissa 

 Primus emarginata 

 *Pachystima Myrsinites 

 */?/< us Jtydbergii 

 CeanotJtus velutinus 



" sanguineus 

 Kalmia microphylla 

 Cassiope Mertensiana 

 (id ultheria humifusa 

 Vaccinium occidentale 



" membranaceum, 

 oreophilum 

 scoparium 

 Symph oricarpos vaccinioides 



#Echinopanax horridum 

 #Cornus X nil all it 

 Ledum glandulosum 

 ^Rhododendron albiflorum 

 Plnjllodoce empetriformis 



" gland ulif era 

 *Menziesia 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 Bebb (Bot. Gaz. 102-108. Ap. 1891), the group 

 Longifoliae, to which belong Salix flu e viatilis y S. me/anopsis, S. exigua, and 

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

 shading off into no other by variation, hybridizing 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 

 Mexican Plateau at the close of the Tertiary. In keeping with this 

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

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

 variability 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 

 coining 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. 



