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Key to Species — Part 20

A. Pacific coast species. Deciduous.

B. Foliage blue with silvery lining. (Q. Douglasii) BLUE OAK

BB. Foliage green.

C. Acorns slenderly conical; branchlets slender, pendulous; leaves white lined.

(Q. lobata) CALIFORNIA WHITE OAK

CC. Acorns oval; branchlets stout, erect; leaves not white lined. (Q. Garryana) PACIFIC POST OAK

AA. Eastern species.

B. Foliage evergreen. (Q. Virginiana) LIVE OAK

BB. Foliage semi-persistent, blue. (Q. breviloba) DURAND OAK

BBB. Foliage deciduous.

C. Leaves pinnately lobed by deep sinuses.

D. Under sides of leaves smooth. (Q. alba) WHITE OAK

DD. Under sides of leaves downy.

E. Branches corky; acorn large, in fringed cup.

(q. macrocarpa) BUR OAK

EE. Branches not corky; acorn medium in size.

F. Acorn globose, enclosed by scaly cup.

(Q. lyrata) OVERCUP OAK

FF. Acorn ovoid, half hid in scaly cup; leaf lobes and sinuses broad, squarish.

(Q. minor) POST OAK

CC. Leaves sinuately dentate with shallow sinuses; linings pale, downy.

D. Lobes of leaves acute. (Q. acuminata) YELLOW OAK

DD. Lobes of leaves rounded.

E. Bark dark brown, deeply furrowed.

(Q. Prinus) CHESTNUT OAK

EE. Bark light grey, scaly.

F. Limbs shedding bark in large flakes;

acorns on long stalks.

(Q. platanoides) SWAMP WHITE OAK

FF. Limbs not shedding bark in flakes; acorns sessile or on short stalks.

(Q. Michauxii) BASKET OAK

The Blue Oak, or Mountain White Oak (Quercus Douglasii, Hook. and Arn.), is a striking and beautiful feature of the landscape of northern and central California. Silvery grey bark and pale blue foliage, deepened by greenish leaf linings, and lightened by their silvery pubescence! No wonder the blue oak attracts attention whether it stands among the scattered groves of California white oak in the broad valleys--a fine, round-headed tree--or climbs the western slopes of the Sierras till it dwindles to a shrub at an altitude of 4,000 feet. It is strangely variable in the shape of its leaves and fruit. Its leaf may have deep lobes like other white oaks, or it may have scarcely any noticeable waves; some leaves are entire, some have pointed, even spiny-tipped lobes like those of the black oaks. The blue of them, however, is a dependable characteristic; also the silky leaf linings.

The acorns are very numerous, and so vividly green in summer that they often overcome much of the blue of the foliage until they take on their rich, chestnut brown. The nut often bulges above the saucer-like cup as if too large for it; often it is elongated into a pencil shape.

The wood is too brittle and the sap wood too thick for use in building. It is an excellent fuel.

California White Oak (Quercus lobata, Nee.)--A large, graceful tree with stout trunk dividing near the ground, with spreading top and pendulous branches, making a broad dome, 80 to 100 feet high, and 150 to 200 feet in diameter. Bark brownish grey, scaly, with shallow furrows, and ridges broken into plates; twigs hoary, grey or reddish brown. Wood hard, fine grained, brittle and hard to season. Buds ovate, small, pubescent. Leaves alternate, variable, oblong or obovate, 2 to 4 inches long, deeply 7 to 11-lobed, thin, firm, pubescent, paler beneath; petioles short, broad, hairy. Flowers with half-grown leaves, February to April, staminate in hairy, yellowish catkins; pistillate, solitary and sessile, as a rule; stigmas broad. Acorns 1 1/4 to 2 1/4 inches long, annual, sessile (rarely stalked), solitary or in pairs, conical, elongated, with sharp, horny, hairy tip; cup shallow, tomentose, with thick scales that become finer toward fringed border; kernel, sweet, edible. Preferred habitat, rich, sandy loam. Distribution, valleys in California west of Sierra Nevada Mountains. Forms open groves, never forests. Uses: Splendid feature of natural scenery, but never successfully cultivated outside of its range. Wood useless except for fuel. Fruit used as food by Indians.

It is a happy circumstance for Californians and for all people who visit "the Land of the Setting Sun" that this valley oak is scorned by all lumbermen. The tree is practically worthless for timber, therefore gigantic individual trees stand scattered or grouped in the spacious valleys of western California, helping to make a landscape that cannot be duplicated this side of England. Indeed, Vancouver, journeying around the world in 1792, was astounded at the park-like Santa Clara Valley, set round with mountains, diversified with hills and intervales, covered with a carpet of verdure, and adorned with majestic oaks. Writing home of this landscape untouched by the hand of man, he says; "It required only to be adorned with the neat habitations of an industrious people to produce a scene not inferior to the most studied effect of taste in the disposal of grounds."

The California white oak is the largest and most graceful of the Western oaks. Its branches end in long shoots that are pendulous like those of the weeping willow. The trunk branches near the ground and rises and spreads out like a great fan. A British elm often has the same habit--our American elm, sometimes. The dome is broader even than that of our Eastern white oak. The twigs are willowy at first, but there is a surprising tortuousness acquired with added years. The limbs are gnarled in the most complex way. "Picturesqueness gone mad" well characterises the expression of the tree in its bare winter aspect.