30 BOTANY OF THE ROUTE. 



but is less than a foot in diameter, and I believe of no especial value as timber. The berries 

 have violent cathartic properties, and, though eaten greedilj' by bears, are not used by the 

 Indians as food. 



A birch (B. occidentalis?) is said to be common north of the straits, but I did not meet with 

 it. A low, shrubby species, east of the Cascade mountains, exudes from its branches a bitter 

 resinous substance, (B. glandulosa.) 



SHEUBBT UNDERGROWTH. 



To complete the description of the forests, I must notice briefly the numerous shrubs which 

 constitute an almost impassable underbrush in most parts of them, and are nearly all of use 

 either for their wood or fruits. In their distribution they are even more local than the trees, 

 and different groups characterize very fully the districts into which the forests are divisible. 

 East of the mountains I have remarked that a peculiar group takes the place of forests on the 

 Great Plains. There is also another group belonging to the Rocky mountain forests which 

 grow along the higher river banks, but, not being in a good condition during my visit there, do 

 not appear in the list of plants collected, though I identified the following species among them : 

 Ehus diversiloba, Torr. & Gray ; Crat^gus sanguinea, Pall., and another species, Cerasus 

 ViRGiNiANA?; Rosa cinnamomea, Linn.; Ribes Aureum, (a fine yellow currant;) R. cereum ; 

 Clematis ligusticsifolia, Nuttall. 



The hazel, (Corylus Americana,) red cornel, or "willow," (Cornus Drummondii,) and bar- 

 berry, are also found on both sides of this range. This latter shrub, absurdly called "Oregon 

 grape," (Berberis aquifolium, the "holly leaved barberry,") extends west to the Coast range 

 only. It produces a blue berry, eatable when cooked, and is much cultivated in the Atlantic 

 States as an ornamental plant. This, with a spirasa, (S. ARiiBFOLiA, ) a ceanothus, (C. Oregonus, ) 

 and the hazel, form 'most of the underbrush of the "fir" forests between the Cascade and 

 Coast ranges. A "mock orange" is also common from the Columbia to Puget Sound, (Phila- 

 delphus.) Three species of raspberry are also found, mostly in this region, (Rdbtjs Nutkanus, 

 leucodermis, and macropetalus,) but to some extent also west of the Coast range. Three 

 species of gooseberrj' have similav limits, though they do not grow in the shade of forests. 

 (Ribes divaricatdm, niveum?, and sanguineum,) and a peculiar rose is found only on the borders 

 of the fir forest, (Rosa gymnocarpa.) On Whidby's island are found two shrubs of much 

 interest on account of their locality, Shepheedia Canadensis and a Rhododendron, closely 

 resembling R. maximum, but perhaps distinct, which extends along the Cascade range into 

 southern Oregon. — {Dr. Neivherry.) 



Near Steilacoom, and in other scattered localities, some of the shrubs belonging to the 

 Rocky mountain group are occasionally found, (Rhus, Ceanothus telutinus, Oreophila myrti- 

 FOLiA.) On the dry prairie two shrubs are met with — the service berry (Amelanchier Cana- 

 densis, var.l alnifolia) of the northern group, and an elder (Sambucus glauca) which belongs 

 to the plains. In the adjoining forests, and often very near it, grows its northern representa- 

 tive, (S. pubens, var. ?) meeting it here just as it does the allied elder of the Atlantic States 

 near New York. Of the shrubs more characteristic of the black spruce forests, but which 

 occur also on the higher and moister parts of the Cascade range, many are evergreen, giving 

 these gloomy forests an undergrowth of almost tropical appearance, though belonging to alpine or 

 boreal families of plants. They do not generally obstruct these forests so much as the pre- 

 ceding group, and, except close to the ocean, they can be easily penetrated along the uplands. 



