24 
OVAL-LEAVED BIRCH. 
BETULA khombifolia, ramis resinosis gracilibus, foliis 
subrhomboideo-ovalibus, vix acutis, grosse serratis, subtus 
pallidioribus epunctatis; venis pilosiusculis amentis foemi- 
neis cylindraceis, squamis tripartitis glabriusculis lobis 
ovatis lateralibus brevibus. 
This is a still more humble shrub than the preceding, 
which it somewhat resembles. It grows in the central 
Rocky Mountain range, and continues more or less to 
the banks of the Oregon. It is spreading and somewhat 
decumbent, with slender brown twigs, which, when 
young, are more or less covered with resinous atoms. 
The leaves, with their petioles, which are 2 or 3 lines, 
are not more than an inch long by J an inch wide, 
oval, and somewhat rhombic, deeply, sharply, and 
almost equally serrate, rounded, but still generally acute, 
smooth above, paler beneath, with a very few distant 
nerves, somewhat hairy along their margins beneath. 
External scales of the male aments ovate, and ciliate. 
Stamens about 6. Female aments with nearly smooth, 
deeply 3-parted scales, of which the central division is 
the longest. I have not seen the ripe fruit. 
Plate VIII. 
A branch of the natural size. a. The seed vessel. 
Obs. On the summit of the White Mountains of New 
Hampshire grows the Betula nana of Europe, found 
there by Mr. Oakes as well as myself. 
Mr. Charles Pickering also collected a specimen on 
