Quercus lobata |
Quercus incana |
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California white oak, roble, valley oak |
bluejack oak |
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Habit | Trees, deciduous, to 25(-35) m, usually with solitary trunks. | Trees, deciduous, to 10 m. Bark dark brown to black with square plates. |
Bark | gray, scaly, deeply checkered in age. |
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Twigs | yellowish, gray, occasionally reddish, 2-4 mm diam., densely or sparsely tomentulose. |
brown to reddish brown, 1-2.5 mm diam., tomentose to sparsely pubescent. |
Buds | yellowish or light brown, ovoid, (2-)3-5(-6) mm, apex occasionally acute, densely pubescent. |
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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 narrowly ovate or elliptic to obovate, usually widest near middle, planar, 30-100 × 12-35 mm, base acute (rarely attenuate) to rounded, margins entire, with 1 apical awn (leaves on juvenile or 2d-flush growth may have 2-3 shallow lobes and 3-5 awns), apex acute or obtuse, rarely rounded; surfaces abaxially densely tomentose, hairs in vein axils often reddish, easily distinguished from others, adaxially often glossy, sparsely pubescent, especially along midrib and near base, veins often raised. |
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. |
biennial; cup saucer-shaped to bowl-shaped, 4.5-8 mm high × 10-18 mm wide, covering 1/4-1/3(-1/2) nut, outer surface pubescent or puberulent, inner surface uniformly pubescent, scale tips tightly appressed, obtuse or acute; nut ovoid (rarely subglobose) to broadly ellipsoid, 10-17 × 10-16 mm, occasionally striate, glabrate, scar diam. 5.5-10.5 mm. |
Cotyledons | distinct. |
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Terminal | buds light brown to reddish brown, narrowly ovoid to conic, 3.5-7 mm, distinctly 5-angled in cross section, scales pubescent, often tuft of reddish or silvery hairs at apex. |
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Quercus lobata |
Quercus incana |
|
Phenology | Flowering late winter–early spring. | Flowering spring. |
Habitat | Valley floors and moderate slopes, open grasslands, savannah and oak woodlands, riparian areas in chaparral | Well-drained sandy soils of barrens, hammocks, dunes, and upland ridges |
Elevation | 0-1700 m (0-5600 ft) | 0-250 m (0-800 ft) |
Distribution |
CA
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AL; AR; FL; GA; LA; MS; NC; OK; SC; TX; VA
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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 incana reportedly hybridizes with Q. falcata [= Q. ×subintegra (Engelmann) Trelease], Q. hemisphaerica (D. M. Hunt 1989), Q. laurifolia (= Q. ×atlantica Ashe), Q. laevis (= Q. ×asheana Little), Q. marilandica (= Q. ×cravenensis Little), Q. nigra (= Q. ×caduca Trelease), and Q. phellos (E. J. Palmer 1948); with Q. pumila (D. M. Hunt 1989); and with Q. velutina (= Q. ×podophylla Trelease), and questionably, Q. myrtifolia. (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. Lobatae |
Sibling taxa | ||
Synonyms | Q. hindsii, Q. lobata var. hindsii, Q. longiglanda | Q. cinerea |
Name authority | Nee.: Anales Ci. Nat. 3: 277. (1801) | W. Bartram: Travels Carolina, 378. (1791) |
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