Quercus arizonica |
Quercus intricata |
|
---|---|---|
Arizona oak, Arizona white oak |
dwarf oak, intricate oak |
|
Habit | Trees, evergreen or subevergreen, small to moderate-sized trees, rarely to 18 m. Bark scaly. | Shrubs, evergreen, clonal, intricately branched. |
Bark | gray, scaly. |
|
Twigs | yellowish, 1.5-2.5 mm diam., persistently felty-tomentose, eventually dingy gray. |
gray- or yellow-tomentose, darkened, 1-1.5 mm diam., persistently pubescent for several seasons. |
Buds | dull russet-brown, ovoid, distally subacute or rounded, 3 mm, sparsely pubescent or glabrate. |
dark reddish brown, 1-1.5 mm, apex round, sparsely pubescent to glabrate. |
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 oblong, sometimes ovate, often strongly cupped, 10-25 × 5-13 mm, extremely thick, leathery, base cuneate to cordate, margins very coarsely revolute, often undulate-crisped, entire, rarely with a few teeth, secondary veins 8 or 9 on each side, apex acute or obtuse; surfaces abaxially brownish or buff, persistently tomentose with erect curly hairs, rarely glabrate in 2d season, midribs (and sometimes principal veins) glabrous and brown against tomentum, secondary veins sometimes prominently raised, usually obscured by tomentum, adaxially dark or gray-green, lustrous, sparsely or moderately stellate-pubescent, secondary veins impressed. |
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 or on peduncle to 15 mm; cup deeply cup-shaped, 7-8 mm deep × ca. 10 mm wide, base round, margin thin, scales ovate or narrower, proximally canescent-tomentose, moderately or markedly tuberculate, tips closely appressed, reddish, thin, nearly glabrous; nut light brown, ovoid, 9-12 × 8-10 mm. |
Cotyledons | connate. |
connate. |
Quercus arizonica |
Quercus intricata |
|
Phenology | Flowering spring. | Flowering spring. |
Habitat | Oak and pinyon woodlands, margins of chaparral, arroyos | Open chaparral and pinyon-oak woodland, on dry, rocky, limestone slopes (in Mexico also on gypsophilous soils) |
Elevation | 1300-2500(-3000) m (4300-8200(-9800) ft) | 1500-2500 m (4900-8200 ft) |
Distribution |
AZ; NM; TX; Mexico (Chihuahua, Coahuila, Durango, and Sonora)
|
TX; Mexico (Coahuila, Nuevo León, Durango, and Zacatecas) |
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.) |
Quercus intricata, a fairly common element of the mountains of the Chihuahuan Desert region, is known in the United States only from two localities: a population in the Chisos Mountains and another in the Eagle Mountains of west Texas. (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. sacame | |
Name authority | Sargent: Gard. & Forest 8: 92. (1895) | Trelease: Mem. Natl. Acad. Sci. 20: 84. (1924) |
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