April 30, 1913 39 
TRAGOPOGON PRATENSIS L. Salsify, Oyster plant. 
Common in fields and in moist areas elsewhere; also in 
Washington county; (Minnesota and Sioux valleys). 
XANTHIUM ECHINATUM Murr. Cocklebur. 
A pest in flooded areas of flood plains; (eastern South Da- 
kota. 
State University, Vermillion, South Dakota. 
THE OAKS OF THE PACIFIC SLOPE—I 
By A. A. HELLER 
While a number of the oaks of the west side of the conti- 
nent become very large, none of them can be classed as lumber 
treeson account of their habit. They develop short thick trunks 
which soon give place to massive, spreading branches, and are 
usually suitable for such lumber only as can be manufactured 
into articles requiring short lengths. Their chief use is for fuel, 
for which purpose they are extensively used, the wood bringing 
a good price. 
Much of the beauty of California valleys and park-like 
slopes is due to the several oaks, both deciduous and evergreen, 
which inhabit them. Many fine examples may be found in the 
Sauta Clara valley south of San Francisco, in Sonoma and Napa 
counties, and in the Sacramento valley. Nearly all of the early 
explorers mention the beautiful oak groves through which they 
passed. ; 
It is my intention in this series of papers to illustrate and 
describe the most important of the oaks found on the Pacific 
‘slope, taking first those belonging to the white oak series. 
QUERCUS LOBATA. Valley oak. 
QUERCUS LOBATA Nee, Anal. Cienc. Nat. 3: 278. 1801. 
The common form of this tree when mature is the one 
shown in plate 6. The average height is about 50 feet, the 
spreading and drooping branches usually extending for a greater 
distance than the height of the tree. The trunk is 2 to § or 
