


THE SYLVA OF MONTANA. 401 
Rep Hawrnonw (C. sanguinea?). The red-berried Haw 
grows sparingly from Walla Walla to Fort Colville, but is 
so similar in leaf to the preceding that it may perhaps be 
only a variety. Specimens of both collected in fruit give 
an opportunity of trying the distinctions of the seedling 
plants. 
Orecon Bearwoop (Frangula Purshiana). This species 
of Buckthorn occurs on both slopes of the Cœur d'Aleüe 
Mountains, but not farther east. With it occurs a low 
ushy species of Rhamesus, as shown by fruiting specimens 
of each collected together. 
OREGON SERVICE-BERRY a alnifolia). I must 
consider this distinct from A. Canadensis of the east, be- 
cause it preserves its peculiarities of leaf, growth and fruit, 
from the eastern base of the Rocky Mountains to the Pacific 
coast, through much variety of climate and soil, differing 
only in height in the drier localities. It attains its greatest 
luxuriance and excellence of fruit in the valley of the Hell 
Gate river, where our whole command feasted on the berries 
for several days. 
Green Doewoop (Cornus pubescens). It was first seen 
near the crossing of Bitterroot river, and extends at inter- 
vals to the west coast. 
Western SUGAR-BERRY (Celtis reticulata). This tree is 
Strictly limited toward the north-west by Snake and Colum- 
bia river, as observed in 1853. It is scarce along them 
and grows only about thirty feet high, with a short trunk 
Sometimes a foot thick. 
OrEGon Oak (Quercus Garryana). This oak does not 
grow east of the eastern base of the Cascade Range, or north 
of the Yakima river, on this side. No oak occurs from the 
Columbus river to Fort Union, on the Missouri, near which 
place is found Q. macrocarpa. No ash grows in a similar 
interval, though one extends to Milk river on the Missouri. 
Gon Asn (Fraxinus Oregona). This first appears at 

