Quercus arizonica |
Quercus kelloggii |
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Arizona oak, Arizona white oak |
California black oak, Kellogg oak |
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Habit | Trees, evergreen or subevergreen, small to moderate-sized trees, rarely to 18 m. Bark scaly. | Trees, deciduous, to 25 m. Bark dark brown to black, ridges broad, irregular. |
Twigs | yellowish, 1.5-2.5 mm diam., persistently felty-tomentose, eventually dingy gray. |
brown to red-brown, (1.5-)2-3.5 mm diam., glabrate. |
Buds | dull russet-brown, ovoid, distally subacute or rounded, 3 mm, sparsely pubescent or glabrate. |
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Leaves | blade elliptic or oblong to narrowly obovate or oblanceolate, planar or moderately convex, to (30-)40-80(-90) × 15-30 mm, thick and leathery, usually stiff, base cordate or rounded and weakly cordate, margins entire or coarsely toothed especially near apex, cartilaginously revolute, teeth mucronate-tipped, obscure or prominent, secondary veins ca. 7-11 on each side, branching, passing into teeth when present, apex acute to usually obtuse or broadly rounded; surfaces abaxially dull, sparsely pubescent or subtomentose with curly branched hairs, reticulate from prominent, raised secondary veins, usually glaucous where exposed, adaxially dark or bluish green, moderately lustrous, sparsely and minutely stellate-pubescent, secondary veins slightly raised or prominent within depressions or impressed. |
blade ovate or broadly elliptic to obovate, 60-200 × 40-140 mm, base cordate to obtuse, occasionally rounded, margins with 7-11 lobes and 13-45 awns, lobes acute to distally expanded, separated by deep sinuses, apex acute; surfaces abaxially glabrous with small axillary tufts of tomentum to densely pubescent, adaxially glabrous to minutely pubescent, veins raised on both surfaces. |
Acorns | solitary or paired, subsessile, occasionally on peduncle to 15 mm; cup hemispheric or cup-shaped, 5-10(-15) mm deep × 10-15 mm wide, enclosing ca. 1/2 nut, base rounded, margin rather coarse, scales cream to brown, broadly ovate, evenly and strongly tuberculate, tomentose, tips closely appressed; nut light brown, ovoid or oblong, 8-12 mm, nearly glabrous. |
biennial; cup saucer-shaped to deeply bowl-shaped, 13-27 mm high × 20-28 mm wide, covering 1/2-2/3 nut, outer surface glabrous to sparsely puberulent, inner surface 1/3 to completely pubescent, scales more than 4 mm long, attenuate or acuminate to acute, smooth, occasionally tuberculate near base of cup, tips loose, especially at margin of cup; nut oblong to broadly ellipsoid, 21-34 × 14-22 mm, puberulent, especially at apex, scar diam. 5.5-10.5 mm. |
Cotyledons | connate. |
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Terminal | buds chestnut brown, ovoid, 4-10 mm, glabrous or with scales ciliate on margins. |
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2n | = 24. |
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Quercus arizonica |
Quercus kelloggii |
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Phenology | Flowering spring. | Flowering late spring. |
Habitat | Oak and pinyon woodlands, margins of chaparral, arroyos | On slopes and valleys of hills and mountains |
Elevation | 1300-2500(-3000) m (4300-8200(-9800) ft) | 300-2400 m (1000-7900 ft) |
Distribution |
AZ; NM; TX; Mexico (Chihuahua, Coahuila, Durango, and Sonora)
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CA; OR
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Discussion | Some of the specimens previously referred to Quercus endemica by C. H. Muller belong here instead. Putative hybrids between Quercus arizonica and Q. grisea (= Q. ×organensis Trelease) are problematic in local areas of contact from southeastern Arizona to western Texas. These intermediates tend to have narrower leaves than Q. arizonica, with moderately reticulate patterns of venation, and more densely hairy leaves. Quercus arizonica and Q. grisea are amply distinct elsewhere, including large areas in northern Mexico, and they appear to be more closely related to other species than to one another (e.g., Q. arizonica with Q. oblongifolia and Q. laeta Liebmann, and Q. grisea with Q. mohriana and Q. microphylla Née). Thus, Q. arizonica and Q. grisea are best treated as distinct species that hybridize, and not as conspecific populations. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
The abundant crops of acorns from Quercus kelloggii were at one time an important food source for Native Americans. The species reportedly hybridizes with Quercus agrifolia (= Q. ×ganderi C. B. Wolf) and Q. wislizenii (= Q. ×morehus Kellogg). (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. sacame | Q. californica, Q. tinctoria var. californica |
Name authority | Sargent: Gard. & Forest 8: 92. (1895) | Newberry: Pacif. Railr. Rep. 6: 28, 89, fig. 6. (1859) |
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