WESTERN BIRCH. 
23 
mond, it occurs on the east side of the Rocky Moun- 
tains down to Edmonton House. Douglas found it near 
springs on the west side of the Rocky Mountains; and 
Doctor Scouler met with it in Oregon, near to the straits 
of Juan de Fuca; it also grows near Walla- Walla, and 
continues up the Oregon to the country of the Flat- 
heads. 
The principal branches are erect and somewhat 
virgate, clothed with a bright brown bark, copiously 
sprinkled with small resinous warts, so as to render the 
branches rough to the touch. The leaves are somewhat 
deltoid, or rhomboidly-ovate, on shortish petioles (in 
my specimens), acute, but not acuminate, sharply and 
somewhat unequally serrated, and very slightly lobed, 
above somewhat glutinous, with very few pinnated 
nerves, below paler; the midrib and nerves sprinkled 
with a few long hirsute hairs, which are also seen above, 
on, and near the petiole. The leaves, in flowering spe- 
cimens, are only about 1J inches long by an inch wide. 
(The adult leaves described by Hooker, are much larger, 
2 to 2^ inches long.) The aments are cylindric, in the 
staminiferous plant, composed of a double series of 
scales. Female aments pedunculated, cylindric, at 
length drooping, often accompanied by a very small leaf 
at the base; the scales trifid and dilated, strongly cili- 
ated, the lateral lobes ovate; the central one nearly 
linear and longer; 3 germs beneath each scale. Nuts 
broadly winged. Styles 2, very long and subulate; 
summit of the germ pubescent. 
The trunk of this species is only a few inches in 
diameter, so that it scarcely ranks with proper trees. 
The leaves are bitter to the taste. 
Plate VII. 
A branch of the natural size. a. The seed vessel. 
