Quercus arizonica |
Quercus durata |
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Arizona oak, Arizona white oak |
leather oak |
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Habit | Trees, evergreen or subevergreen, small to moderate-sized trees, rarely to 18 m. Bark scaly. | Shrubs, evergreen, 1-2(-3) m. Bark scaly. | ||||
Twigs | yellowish, 1.5-2.5 mm diam., persistently felty-tomentose, eventually dingy gray. |
gray or yellowish, 1-3 mm diam., densely or sparsely tomentulose, often with prominent, yellowish, spreading hairs. |
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Buds | dull russet-brown, ovoid, distally subacute or rounded, 3 mm, sparsely pubescent or glabrate. |
brown or reddish brown, ovoid or globose, 1-2 mm, glabrous or puberulent. |
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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 cupped or convex, rarely somewhat planar, (10-)15-40 × 7-15(-20) mm, base cuneate, rounded-attenuate, or truncate, margins entire or irregularly toothed, sometimes spinose, usually unevenly revolute, secondary veins 4-6 on each side, apex rounded or subacute; surfaces abaxially densely to sparsely covered with erect, stipitate, (1-)2-4(-6)-rayed hairs 1-4 mm, felty to touch, secondary veins prominent, adaxially grayish or yellowish, with dense or scattered, semi-erect or appressed hairs, secondary veins obscure or somewhat impressed. |
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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. |
solitary or paired, subsessile; cup reddish, hemispheric, deeply cup-shaped or turbinate, 4-6 mm deep × 12-18 mm wide, enclosing to 1/2 nut or more, scales reddish or yellowish, weakly to strongly tuberculate, often somewhat glandular; nut globose, ovoid or cylindric, 15-25 × 10-25 mm, apex rounded or obtuse, persistently minute-puberulent. |
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Cotyledons | connate. |
distinct. |
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Quercus arizonica |
Quercus durata |
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Phenology | Flowering spring. | |||||
Habitat | Oak and pinyon woodlands, margins of chaparral, arroyos | |||||
Elevation | 1300-2500(-3000) m (4300-8200(-9800) ft) | |||||
Distribution |
AZ; NM; TX; Mexico (Chihuahua, Coahuila, Durango, and Sonora)
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CA
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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.) |
Chaparral, oak woodlands, open pine forests, on serpentine and nonserpentine soils; 150-1500 m. Varieties 2 (2 in the flora). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 3. | FNA vol. 3. | ||||
Parent taxa | Fagaceae > Quercus > sect. Quercus | Fagaceae > Quercus > sect. Quercus | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | Q. sacame | Q. dumosa var. bullata, Q. dumosa var. revoluta | ||||
Name authority | Sargent: Gard. & Forest 8: 92. (1895) | Jepson: Fl. Calif. 1(2): 356. (1909) | ||||
Web links |