8 Miscellaneous Circular 31, U. S. Dept. of Agriculture 



taken from the San Mateo peninsula 

 to the San Francisco florist shops in 

 the fall. The acorns are bright chest- 

 nut in color and slender, have close, 

 scaly cups, and vary greatly in size. 

 The trunk is ashen gray and is of the 

 white-oak type. 



The Blue Oak, appropriately so 

 called because of the blue tone of its 

 foliage, is another white-trunked tree. 

 It occurs on the interior slopes of the 

 Coast Range and the west slopes of 

 the Sierras, in the same dry, sunny 

 conditions that delight the Digger 

 Pine. These trees once covered the 

 foothills in open stands for many 

 miles from Mendocino and the moun- 

 tains south of Shasta clear to the 

 Tehachapi. It is the oak that named 





Fig. 10.— Valley Oak (Quercus 



LOB ATA) 



Paso Robles and that occurs on the 

 Carriso Plains. For years it furnished 

 the firewood of Stockton, Modesto, 

 Merced, Madera, Fresno, and Tulare, 

 but the easily accessible supply has 

 now disappeared. The leaves of this 

 oak are " wavy " at the edges, but are 

 not deeply incut like those of the Val- 

 ley Oak, and the acorns are blunter 

 and thicker in proportion to their 

 length. The tree is seldom over 40 

 feet high and 20 inches in diameter, 

 although rare specimens have been 

 found with a diameter of 2 feet and 

 a height of 75 feet. 



Next in range of altitude, but over- 

 lapping the Valley and the Blue Oaks, 



comes the California Black Oak. 

 The hard, deeply furrowed bark of 

 this tree is very dark, seeming black 

 when wet and bare. After the soft 

 pink leaves of the spring mature into 

 the great, shiny, dark yellow-green 

 ones of summer, however, little of the 

 trunk is visible beyond the first few 

 feet above the ground. The leaves of 

 this oak are similar in shape to those 

 of the Valley Oak, but are longer (4 to 

 6 inches) and deeper green. The 

 acorns vary in size, are pale chestnut 

 in color, and downy at the top end. 

 The cups are scaly, with the lowest 

 scales much thickened. This oak oc- 

 curs from central Oregon to the Mexi- 

 can border, not on the plains or near 

 the sea, but usually from 1,500 feet 

 up to 5,000 or 7,000 feet, where it 

 meets and mingles with the Western 

 Yellow Pine and Firs. It is at its 

 best in the Sierras at 3,000 feet, where 

 it is the principal oak species, fur- 

 nishing many Indians with what was 

 once their main dependence for food, 

 and is even yet a favorite item in their 

 diet — acorn-meal mush. It also fur- 

 nishes firewood for the mountain peo- 

 ple and mast for their hogs. Califor- 

 nia Black Oak is the principal oak in 

 the Yosemite Valley. 



The White Oak of British Columbia 

 and Washington, the largest and most 

 abundant oak of Oregon and there 

 called the Oregon Oak, is our Garry- 

 Oak. It is commonly 25 to 55 feet 

 high in California and is abundant in 

 the Bald Hills region, inside the red- 

 wood belt of Mendocino and Hum- 

 boldt Counties. It is found rather 

 frequently as far south as the east 

 side of Santa Rosa Valley, and rarely 

 in the Santa Cruz Mountains. The 5 

 to 7 lobed leaves are large and of a 

 dark, shining green. The trunk bark 

 is white and cut into broad plates 

 by shallow fissures. The shiny acorns 

 of the Garry Oak differ from the 

 acorns of the other large oaks of Cali- 

 fornia. They are almost round (one- 

 fourth to l 1 /! inches long by two- 

 thirds to 1 inch thick) and bulge out 

 of very shallow cups. 



The evergreen or "live oaks" form 

 a distinct class, in which three or 

 four stand out conspicuously. This 

 indefinite number is used because one 

 of them, the Tanbark Oak, is not 

 called an oak at all by some botanists, 

 but is classed with the Pasanias, of 

 which there are over a hundred species 

 in southern Asia, though only this one 

 grows in California. These Pasanias 

 are as nearly related to the chestnut 

 as to the oaks, have chestnutlike 

 leaves and upright catkins like a 



