LET’S KNOW SOME TREES 25 
live oak, at 3,000 to 4,000 feet, on dry exposures, is the scrubbiest 
kind of a scrub oak. Once one’s eyes are opened to the brush, it is 
delightful to come across a thicket or a single specimen of tough- 
twigged scrub that has acorns on it. 
THE WILLOWS 
In spite of California town camps, forest camps, and park camps 
to which pure water is piped, we enjoy camping by stream sides best 
of all. Here we have a chance to get acquainted with many sorts 
of water-loving trees, among them the willows of which about nine 
tree species occur natively in California. 
Perhaps the weeping willow is the mind picture that comes to all 
of us; but that sort, though a favorite near the wells of our grand- 
fathers, was planted there and is not native to North America. 
Seven of the nine native tree willows have the long-pointed narrow 
leaf typical of most willows, the other two—the white willow, and 
the Dudley willow, distinguished by their light or dark gray bark— 
have leaves broader in proportion to their length and rounded at 
the ends. Nearly all willows have at the foot of each leaf stem a 
pair of odd little often ear-shaped, leaflike growths (stipules) that 
are sometimes dropped during the summer, but most often persist 
and help us to distinguish willows from other trees. All the wil- 
lows, too, have catkins (beginning before the leaves as pussy willows) 
for blossoms, and all have quinine-bitter bark. 
California willows are seldom, if ever, over 50 feet high, and more 
often are from 20 to 40; the mountain sorts are still smaller and 
divided into many stems. 
Even well-trained botanists, with all material at hand and a good 
glass, sometimes have difficulty in distinguishing one species of 
willow from another. It is enough for the rest of us to know that 
a willow is a willow and to enjoy its beauty and shade from the 
‘pussies ” of spring to the lemon-yellow foliage of fall. 
THE POPLARS 
There are three sorts of these water-loving trees in California— 
the aspen of the mountains, the black cottonwood of the foothill 
canyons, and the Fremont cottonwood of the lower: valleys. All 
have heart-shaped leaves that turn yellow in the fall; their bloom 
is a pendant catkin—or rather two catkins—one bearing the pollen 
dust on the male tree, the other eventually producing the “ cotton ” 
on the female tree. The poplars and the willows grow under simi- 
lar conditions and are often found together. 
Most of us are lucky enough to know the little aspen—the “ quak- 
ing asp” (fig. 17)—for it grows in Alaska, Canada, the eastern 
United States as far south as Missouri, the Western States, and 
Mexico, at elevations varying from sea level to over 10,000 feet. 
It is the tree whose small heart-shaped leaves dance at the slightest 
breeze. A group at the other end of a meadow or a whole hillside 
of them, golden yellow in the fall, with a leaf here and there float- 
ing away on the wind, is a never-to-be-forgotten sight. 
