Quercus vacciniifolia |
Quercus hypoleucoides |
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huckleberry oak |
silverleaf oak |
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Habit | Shrubs, low spreading to often prostrate, to 1.5 m. Twigs branching at 45° angles or less, reddish brown, 1-1.5 mm diam., flexible, glabrous to sparsely pubesent. | Trees or shrubs, evergreen, to 10 m. Bark black, deeply furrowed. |
Twigs | dark reddish brown, 1.5-3 mm diam., pubescent. |
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Leaves | blade oblong-ovate, 10-35 × 7-15 mm, flat, thin, leathery, base slightly rounded to acute, secondary veins inconspicuous, 6-8 pairs, branching at 45-60° angles, with weakly thickened cell walls, margins entire or indistinctly and irregularly mucronately toothed, apex acute or rarely obtuse; surfaces abaxially whitish green with waxy layer, glabrous or slightly pubescent with stellate hairs, adaxially dull gray-green, glabrous or sparsely pubescent with stellate hairs. |
blade narrowly ovate to ovate or elliptic, 45-120 × 15-40 mm, base cuneate to rounded, margins strongly revolute, entire or spinose with up to 11 awns, apex acute to attenuate; surfaces abaxially densely tawny- or white-tomentose, adaxially noticeably rugose, glabrous. |
Acorns | solitary or rarely paired; cup shallowly saucer-shaped to slightly turbinate, 3-4 mm deep × 10-15 mm wide, scales appressed, slightly embedded, moderately silvery brown-pubescent; nut ovoid, 8-17 × 5-10 mm, apex acute; nut scar to 3 mm diam. |
annual or biennial; cup deeply saucer- or cup-shaped, 4.5-7 mm high × 6-13 mm wide, covering 1/3 nut or less, outer surface pubescent to sparsely puberulent, inner surface pubescent to floccose, scales appressed, blunt; nut ellipsoid to oblong, 8-16 × 5-10 mm, glabrous, scar diam. 2.5-5.5 mm. |
Terminal | buds conic, 2.5 mm, scales brown with ciliate margins. |
buds light chestnut brown, ovoid, 2.5-4.5 mm, glabrous except for ciliate scale margins, occasionally with tuft of hairs at apex. |
Quercus vacciniifolia |
Quercus hypoleucoides |
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Phenology | Flowering in early summer. | Flowering spring. |
Habitat | Dry ridges, steep slopes, and rocky areas from montane coniferous zone to near treeline | Common in moist canyons and on ridges |
Elevation | 900-2800 m (3000-9200 ft) | 1500-2700 m (4900-8900 ft) |
Distribution |
CA; NV; OR
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AZ; NM; TX; n Mexico
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Discussion | Typical high-elevation populations in the Sierra Nevada of California can be distinguished from all shrubby forms of Quercus chrysolepis by the absence of glandular trichomes and by thin cups with small nut-attachment scars. At lower elevations in northern California and southwestern Oregon, secondary contact with Q. chrysolepis has resulted in the formation of hybrids. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Quercus hypoleucoides reportedly hybridizes with Q. gravesii (Q. ×inconstans E. J. Palmer [= Q. livermorensis C. H. Muller]) (see C. H. Muller 1951). Several specimens from Pima County, Arizona, fall outside the range of typical Q. hypoleucoides, suggesting hybridization with the Mexican Q. mcvaughii Spellenberg (R. Spellenberg 1992). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 3. | FNA vol. 3. |
Parent taxa | Fagaceae > Quercus > sect. Protobalanus | Fagaceae > Quercus > sect. Lobatae |
Sibling taxa | ||
Synonyms | Q. hypoleuca | |
Name authority | Hittell: Resources Calif. 101. (1863) — (as vaccinifolia) | A. Camus: Bull. Mus. Natl. Hist. Nat., sér. 2, 4: 124. (1932) |
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