263 Geology and Botany of Northern Pacific Railroad. 



sides are many cottouwoods (Populus trichocarpa) , the Oregon 

 ash (Fraxinus Oregona), and an arborescent alder (Alnns rhom- 

 bifolia), which reaches an altitude of 60 feet, with a trunk-diam- 

 eter of 12 to 15 inches. On the dryer and higher ground is 

 found Finns ponderosa, and on the lower, thickets of P. contorta, 

 often growing like canes in a cane-brake. Scattered through 

 this lowland forest are also the two arborescent maples of the 

 west, Acer macrophyllum and A. circinnatum. Of these the 

 latter, called the vine maple, is a peculiar feature in the forests 

 of the Lower Columbia, Puget's Sound, and Vancouver's Island. 

 It is rarely more than six inches in diameter, the trunks very 

 slender, and several springing from the same root. These droop, 

 and reaching the ground, frequently take root at the summit. 

 Where these interlacing trunks are numerous, they form a thicket 

 which is almost impenetrable. To this meagre list of angio- 

 spermous trees, I should add Garry's oak and the Madrona (Quer- 

 cus Garryana, and Arbutus Menziesii). The oak, scattered 

 about the open grounds of the Willamette Valley and Puget's 

 Sound, occasionally attains a diameter of three or four feet, but 

 with a spreading and irregular growth and brittle wood, so that 

 it has little value as a timber tree. The " Madrona" is a small 

 tree, but much admired for the beauty of its foliage, and the pe- 

 culiarity of its bark. The former is persistent and rich, and the 

 latter exfoliates in brown and greenish layers of different shades. 

 The undergrowth of the Pacific coast forest, where the latter is 

 not too dense, is abundant and varied. Over the rocks and fallen 

 tree-trunks is a thick mat of mosses, which grow with a luxuri- 

 ance and exhibit a variety nowhere rivalled in the eastern States. 

 Ferns are less numerous than might be expected in this moist 

 climate, but a few species are abundant and grow with great 

 luxuriance. The most common is the cosmopolitan bracken 

 (Pteris aqtiilina), the next, Aspidium munitum, strikingly 

 like our eastern A. acrostichoides, but having a much stronger 

 growth. Of the less numerous species, a respectable list could 

 be made, but on the whole the ferns are not an important ele- 

 ment in vegetation. Of the under-shrubs, the most striking is 

 Fatsia Jiorrida ; this has the aspect of an Aralia ; it has a thick 

 woody stem six to ten feet long, somewhat decumbent at base, 

 but bearing above a number of large palmate leaves. Both stem 



