24 MISC. CIRCULAR 31, U. S. DEPT. OF AGRICULTURE 
SCRUB OAKS 
One of the most interesting and useful groups of trees is that 
which goes under the name of “scrub oaks.” They are really not 
trees at all, but bushes from 4 to 12 feet high. They are great soil 
makers and soil holders, often growing in dense thickets on open, dry 
ridges, slowly breaking into the rock that lies so near the surface and 
holding the soil they make by the network of their roots. Over 
thousands of acres they are all that keep the winter rains from sluic- 
ing the surface soil off the rocks, thus filling.up the artificial lakes 
with sand or breaking the dams with a sudden rush of water. One 
hears the facetious laugh at some of the southern California brush — 
“ forests,” and ask if there is a tree in them. But it is the protec- 
tion afforded by these very scrub oaks, so absurdly unforestlike in 
appearance, which is really responsible for some of Mother Nature’s 
most effective forestry in California. 
The principal bush oak in the northern part of the State, from 
the Oregon border to the Kaweah Basin in Tulare County, is the 
Brewer oak, a beautiful little thicket-forming shrub, sometimes a 
lovely round-headed miniature tree, with good-sized acorns. The 
leaves of Brewer oak are lobed like those of Oregon white (Garry) 
oak, but are much smaller—114 to 314 inches long—while the stems 
or trunks are 2 to 4 inches in diameter, gray in color. After the 
leaves drop in the late fall a hill slope of Brewer oaks looks all 
gray, like a mist on the mountain. 
The California scrub oak, the principal scrub oak of the southern 
part of the State, appropriately bears the specific name dumosa. It 
is seldom over 8 feet high and has a great variety of leaf forms, 
sometimes producing on the same plant leaves with smooth edges, 
leaves twisted at the edges and set with prickers, and leaves deeply 
lobed. The general effect, however, is of pricker-edged leaves. Try 
to force your way through a thicket of California scrub oak and 
you will indorse this statement. The oval acorns, from three- 
fourths to 114 inches in length, aré set in shallow saucers rather 
than im cups; these saucers look as if they had been quilted. In 
size and shape the acorns vary almost as much as the leaves. The 
leaves of one season stay until the next spring’s growth pushes 
them off. 
Away up in the northwestern corner of the State; and extending 
into southwestern Oregon, is a most interesting shrub, the Sadler oak, 
the sole Pacific representative of the chestnut oak group. Occasion- 
ally reaching a height of 8 feet, it is more often under 3 feet in 
height, but has surprisingly large leaves for such a small oak. These 
leaves, 3 to 4 inches long, are heavily veined on the underside, the 
veins ending like prickles that beset the edges of the leaves. The 
leaf stems, one-half inch or more long, are positively furry with 
rust-colored hairs. 
In addition to these three distinct sorts of scrub oak there are 
varieties of the taller oaks. The huckleberry oak, for instance, has 
by some been considered a bush variety of the canyon live oak, and 
looks like an exquisite miniature of its big brother. The canyon 
live oak itself forms round green shrubs that cling to the sides of 
such canyons as the Yosemite and Kings River, and the highland 
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