Quercus densiflora Hook. & Arn.
Pasania densiflora Örst.

Leaves oblong or oblong-obovate, rounded or acute or rarely cordate at base, acute or occasionally rounded at apex, or rarely lanceolate and acuminate (f. lanceolata Rehdr.) repand-dentate, with acute callous teeth, or entire with thickened revolute margins, coated when they unfold with fulvous tomentum and glandular on the margins with dark caducous glands, at maturity pale green, lustrous and glabrous or covered with scattered pubescence on the upper surface, rusty-tomentose on the lower, ultimately becoming glabrous above and glabrate and bluish white below, 3′—5′ long, ¾′—3′ wide, with a midrib raised and rounded on the upper side, thin or thick primary veins and fine conspicuous reticulate veinlets; persistent until the end of their third or fourth year; petioles stout, rigid, tomentose, ½′—¾′ in length; stipules brown and scarious, hirsute on the outer surface. Flowers in early spring and frequently also irregularly during the autumn; aments stout-stemmed, 3′—4′ long; staminate flowers crowded, hoary-tomentose in the bud, their bracts tomentose. Fruit solitary or often in pairs, on a stout tomentose peduncle ½′—1′ in length; nut full and rounded at base, gradually narrowed and acute or rounded at apex, scurfy-pubescent when fully grown, becoming light yellow-brown, glabrous and lustrous at maturity, ¾′—1′ long, ½′—1′ thick, its cup shallow, tomentose with lustrous red-brown hairs on the inner surface, and covered by long linear rigid spreading or recurved light brown scales coated with fascicled hairs, frequently tipped, especially while young, with dark red glands and often tomentose near the base of the cup.

A tree, usually 70°—80° but sometimes 150° high, with a trunk 1°—4° in diameter, stout branches ascending in the forest and forming a narrow spire-like head, or in open positions spreading horizontally and forming a broad dense symmetrical round-topped crown, and branchlets coated at first with a thick fulvous tomentum of fascicled hairs often persistent until the second or third year, becoming dark reddish brown and frequently covered with a glaucous bloom; or sometimes reduced to a shrub, with slender stems only a few feet high (var. montana Rehdr.). Winter-buds ovoid, obtuse, ¼′—⅓′ long, often surrounded by the persistent stipules of the upper leaves, with tomentose loosely imbricated scales, those of the outer ranks linear-lanceolate, increasing in width toward the interior of the bud, those of the inner ranks ovate or obovate and rounded at apex. Bark ¾′—1½′ thick, deeply divided by narrow fissures into broad rounded ridges broken into nearly square plates covered by closely appressed light red-brown scales. Wood hard, strong, close-grained, brittle, reddish brown, with thick darker brown sapwood; largely used as fuel. The bark is exceedingly rich in tannin and is largely used for tanning leather.

Distribution. Valley of the Umpqua River, Oregon, southward through the coast ranges to the Santa Inez Mountains, California, and along the western slope of the Sierra Nevada up to elevations of 4000° above the sea to Mariposa County; very abundant in the humid coast region north of San Francisco Bay and on the Santa Cruz and Santa Lucia Mountains, and of its largest size in the Redwood forest of Napa and Mendocino Counties; southward and on the Sierras less abundant and of smaller size; the form lanceolata in southern Oregon and in Del Norte and Mendocino Counties, California; the var. montana at high altitudes on the Siskiyou Mountains, in the region of Mount Shasta and on the northern Sierra Nevada.

5. QUERCUS L. Oak.

Trees or shrubs, with astringent properties, pubescence of fascicled hairs, scaly or dark and furrowed bark, hard and close-grained or porous brittle wood, slender branchlets marked by pale lenticels and more or less prominently 5-angled. Winter-buds clustered at the ends of the branchlets, with numerous membranaceous chestnut-brown slightly accrescent caducous scales closely imbricated in 5 ranks, in falling marking the base of the branchlet with ring-like scars. Leaves 5-ranked, lobed, dentate or entire, often variable on the same branch, membranaceous or coriaceous, the primary veins prominent and extending to the margins or united within them and connected by more or less reticulate veinlets, deciduous in the autumn or persistent until spring or until their third or fourth year; petioles in falling leaving slightly elevated semiorbicular more or less obcordate leaf-scars broader than high, marked by the ends of numerous scattered fibro-vascular bundles; stipules obovate to lanceolate, scarious, caducous, or those of upper leaves occasionally persistent through the season. Flowers vernal with or after the unfolding of the leaves; staminate solitary in the axils of lanceolate acute caducous bracts, or without bracts, in graceful pendulous clustered aments, from separate or leaf-buds in the axils of leaves of the previous year, or from the axils of the inner scales of the terminal bud or from those of the leaves of the year; calyx campanulate, lobed or divided to the base into 4—7, usually 6, membranaceous lobes; stamens 4—6, rarely 2, or 10—12, inserted on the slightly thickened torus, with free filiform exserted filaments and ovate-oblong or subglobose glabrous or rarely hairy 2-celled usually yellow anthers; pistillate solitary, subtended by a caducous bract and 2 bractlets, in short or elongated few-flowered spikes from the axils of leaves of the year; calyx urn-shaped, with a short campanulate 6-lobed limb, the tube adnate to the incompletely 3 or rarely 4 or 5-celled ovary inclosed more or less completely by an accrescent involucre of imbricated scales, becoming the cup of the fruit; styles as many as the cells of the ovary, short or elongated, erect or incurved, dilated above, stigmatic on the inner face or at apex only, generally persistent on the fruit; ovules anatropous or semianatropous, 2 in each cell. Fruit a nut (acorn) maturing in one or in two years, ovoid, subglobose, or turbinate, short-pointed at apex, 1-seeded by abortion, marked at base by a large conspicuous circular scar, with a thick shell, glabrous or coated on the inner surface with pale tomentum, more or less surrounded or inclosed in the accrescent cupular involucre of the flower (cup), its scales thin or thickened, loosely or closely imbricated. Seed marked at base or at apex or rarely on the side by the abortive ovules; cotyledons thick and fleshy, usually plano-convex and entire.

Quercus inhabits the temperate regions of the northern hemisphere and high altitudes within the tropics, ranging in the New World southward to the mountains of Colombia and in the Old World to the Indian Archipelago. Two hundred and seventy-five species have been described; of the North American species fifty-four are large or small trees. Of exotic species, the European Quercus Robur L., and Quercus sessiliflora Salisb., have been frequently cultivated as ornamental trees in the eastern United States, where, however, they are usually short-lived and unsatisfactory. Many of the species are important timber-trees; their bark is often rich in tannin and is used for tanning leather, and all produce wood valuable for fuel and in the manufacture of charcoal.

Quercus is the classical name of the Oak-tree.

CONSPECTUS OF THE NORTH AMERICAN ARBORESCENT SPECIES.