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,