A tree, 25°—30° high, with a short trunk 6′—8′ in diameter, dividing not far from the ground into numerous stout wide-spreading branches forming a broad irregular head, and slender branchlets bright red-brown more or less thickly coated with pale tomentum at midsummer, covered during their second and third years with thin dark brown nearly black bark broken into small thin closely appressed scales. Wood light brown, with thick pale sapwood.
Distribution. Forming an open forest on the Mule Mountains, Cochise County, southeastern Arizona.
32. [Quercus arizonica] Sarg. White Oak.
Leaves oblong-lanceolate to broadly obovate, generally acute or sometimes rounded at apex, rounded or cordate at base, repandly spinose-dentate usually, except on vigorous shoots, only above the middle or toward the apex, or entire and sometimes undulate on the margins, when they unfold light red clothed with bright fulvous tomentum and furnished with dark dental glands, at maturity thick, firm and rigid, dull dark blue-green and glabrate above, duller and covered with thick fulvous or pale pubescence below, 1′—4′ long, ½′—2′ wide, with a broad yellow midrib, slender primary veins, arcuate and united near the thickened revolute margins, and coarsely reticulate veinlets; falling in the early spring just before the appearance of the new leaves; petioles stout, tomentose, ¼′—½′ in length. Flowers: staminate in tomentose aments 2′—3′ long; calyx pale yellow, pubescent, and divided into 4—7 broad acute ciliate lobes; anthers red or yellow; pistillate on short stems tomentose like their involucral scales. Fruit sessile or on hoary-tomentose stems rarely ½′ long, usually solitary, ripening irregularly from September to November; nut oblong, oval or slightly obovoid, obtuse and rounded at the puberulous apex, ¾′—1′ long, ½′ thick, dark chestnut-brown, lustrous and often striate, soon becoming light brown, inclosed for half its length in a cup-shaped or hemispheric cup light brown and pubescent within, covered by regularly and closely imbricated scales coated with pale tomentum and ending in thin light red pointed tips, those below the middle of the cup much thickened and rounded on the back; seed dark purple, very astringent.
A tree, occasionally 50°—60° tall, with a trunk 3°—4° in diameter, and thick contorted branches spreading nearly at right angles and forming a handsome round-topped symmetrical head, and stout branchlets clothed at first with thick fulvous tomentum persistent during their first winter, reddish brown or light orange color and pubescent or puberulous in their second season, ultimately glabrous and darker; usually not more than 30°—40° tall; at high elevations reduced to a low shrub. Winter-buds subglobose, about 1/16′ long, with loosely imbricated bright chestnut-brown puberulous scales ciliate on the margins. Bark of young stems and branches thin, pale, scaly with small appressed scales, becoming on old trunks about 1′ thick and deeply divided by narrow fissures into broad ridges broken into long thick plate-like scales pale or ashy gray on the surface. Wood heavy, strong, hard, close-grained, dark brown or nearly black, with thick lighter colored sapwood; used only for fuel.
Distribution. The most common and generally distributed White Oak of southern New Mexico and Arizona, covering the slopes of cañons of mountain ranges at altitudes of from 5000°—10,000° above the sea, often ascending nearly to the summits of the high peaks; and in northern Mexico.
33. [Quercus oblongifolia] Torr. White Oak.
Leaves ovate, elliptic, or slightly obovate, rounded and occasionally emarginate or acute at apex, usually cordate or occasionally rounded at base, entire and sometimes undulate with thickened revolute margins, or remotely dentate with small callous teeth, on vigorous shoots and young plants oblong, rounded or cuneate at the narrow base, coarsely sinuate or undulate-toothed or 3-toothed at the broad apex and entire below, when they unfold bright red and coated with deciduous hoary tomentum, at maturity thin and firm, blue-green and lustrous above, paler below, 1′—2′ long, ½′—¾′ wide, or on vigorous shoots sometimes 3′—4′ long, with a prominent pale midrib, slender primary veins, and conspicuous reticulate veinlets; persistent during the winter without change of color, gradually turning yellow in the spring and falling at the appearance of the new leaves; petioles stout, nearly terete, about ¼′ in length. Flowers: staminate in short hoary-tomentose aments; calyx bright yellow, pilose, divided into 5 or 6 laciniately cut or entire acute segments tinged with red above the middle; pistillate usually sessile, or on peduncles tomentose like the involucral scales; stigmas bright red. Fruit usually solitary and sessile, rarely long-stalked; nut ovoid, ellipsoidal, or slightly obovoid, full and rounded at apex surrounded by a narrow ring of white pubescence, dark chestnut-brown, striate, and very lustrous, soon becoming light brown in drying, ½′—¾′ long, about ⅓′ thick, inclosed for about one third its length in a cup-shaped or rarely turbinate thin cup yellow-green and pubescent on the inner surface and covered by ovate-oblong scales slightly thickened on the back, coated with hoary tomentum and ending in thin acute bright red tips ciliate on the margins and sometimes forming a minute fringe to the rim of the cup.