Quercus lobata |
Quercus depressipes |
|
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California white oak, roble, valley oak |
Davis Mountain oak, depressed oak |
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Habit | Trees, deciduous, to 25(-35) m, usually with solitary trunks. | Shrubs, evergreen or subevergreen, low, to 1 m, often forming dense thickets, rhizomatous. |
Bark | gray, scaly, deeply checkered in age. |
gray, scaly. |
Twigs | yellowish, gray, occasionally reddish, 2-4 mm diam., densely or sparsely tomentulose. |
tan-brown, becoming reddish gray, 1-1.5 mm diam., glabrate or hairy. |
Buds | yellowish or light brown, ovoid, (2-)3-5(-6) mm, apex occasionally acute, densely pubescent. |
tan or brown, subglobose, 1-1.5 mm, glabrate or scales inconspicuously ciliate. |
Leaves | blade broadly obovate or elliptic, moderately to deeply lobed, (40-)50-100(-120) × 30-60(-75) mm, base rounded-attenuate, cuneate, or truncate, rarely subcordate, margins with sinuses usually reaching more than 1/2 distance to midrib, lobes oblong or spatulate, obtuse, rounded, or blunt, secondary veins 5-10 on each side, apex broadly rounded; surfaces abaxially whitish or light green, densely to sparsely covered with interlocking appressed or semi-erect, 8-10(-14)-rayed stellate hairs, adaxially dark green or grayish, glossy or somewhat scurfy because of sparse stellate hairs. |
blade oblong to elliptic, 10-25(-60) × 8-25 mm, thick, leathery, base moderately to deeply cordate, petiole strongly depressed in basal sinus, margins inconspicuously toothed in distal 1/2, rarely entire, sometimes sublobate, somewhat revolute, secondary veins 5 or 6 on each side with few intermediates, branching, apex broadly rounded to subacute; surfaces abaxially dull gray-green or glaucous, completely glabrous or with a few stellate hairs on midrib, adaxially similar to abaxial surface, secondary veins somewhat raised on both surfaces. |
Acorns | solitary or paired, subsessile; cup deeply cup-shaped, hemispheric or turbinate, rim thick, 10-30 mm deep × 14-30 mm wide, scales grayish or cream, more acute near rim, strongly and irregularly tuberculate, especially toward base of cup; nut light brown, oblong or fusiform, 30-60 × (12-)15-25 mm, tapering to acute or rounded apex. |
paired on peduncle 7-15 mm; cup 4-7 mm deep × 8-13 mm wide, goblet-shaped, enclosing 1/4-1/2 nut, base somewhat constricted or rounded, scales moderately tuberculate, proximally densely gray-tomentose, tips rather closely appressed, reddish brown, abaxially glabrous, ciliate; nut tan-brown, elliptic to ovoid or globose, to 10-15 × 10-11 mm, apex rounded, glabrous. |
Cotyledons | distinct. |
connate. |
Quercus lobata |
Quercus depressipes |
|
Phenology | Flowering late winter–early spring. | Flowering spring. |
Habitat | Valley floors and moderate slopes, open grasslands, savannah and oak woodlands, riparian areas in chaparral | Grassland and open wooded slopes |
Elevation | 0-1700 m (0-5600 ft) | 2100-2600 m (6900-8500 ft) |
Distribution |
CA
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TX; Mexico (Chihuahua, Durango, and Zacatecas) |
Discussion | Mature trees of Quercus lobata are among the largest oaks of the United States. The species hybridizes with numerous other species, but the hybrids are not common in most parts of its range. On Santa Cruz and Santa Catalina islands, however, occur extensive and relatively stable populations that show intermediate characteristics with Q. pacifica (see treatment). The hybrids have been given the name Q. ×macdonaldii, and they differ from Q. lobata in the following: leaf sinuses reaching less than half the distance to the midrib; leaves usually smaller, the lobes often more acute and brighter green; and acorns smaller, with more acute apices. The Yuri used Quercus lobata in the treatment of diarrhea (D. E. Moerman 1986). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Quercus depressipes enters the United States in only one population on the highest portion of Mt. Livermore in trans-Pecos Texas; it has a wider distribution in the dry altiplano of northern Mexico. Its most distinctive characteristics are the combination of dwarf clonal habit, small glaucous leaves without spinose teeth, and connate cotyledons. In northern Mexico, it hybridizes locally with Q. rugosa. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 3. | FNA vol. 3. |
Parent taxa | Fagaceae > Quercus > sect. Quercus | Fagaceae > Quercus > sect. Quercus |
Sibling taxa | ||
Synonyms | Q. hindsii, Q. lobata var. hindsii, Q. longiglanda | Q. bocoynensis |
Name authority | Nee.: Anales Ci. Nat. 3: 277. (1801) | Trelease: Mem. Natl. Acad. Sci. 20: 90. (1924) |
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