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bluejack oak

Chihuahua oak, Chihuahuan oak, felt oak

Habit Trees, deciduous, to 10 m. Bark dark brown to black with square plates. Shrubs or trees, deciduous, to 10 m. Bark gray, furrowed, checkered, or scaly.
Twigs

brown to reddish brown, 1-2.5 mm diam., tomentose to sparsely pubescent.

gray, 2-3(-4) mm diam., densely tomentose.

Buds

reddish brown, broadly ovoid, distally rounded, 2-2.5 mm, densely yellowish pubescent;

scales gray-puberulent;

stipules persistent, 1-4, subulate, pubescent, at base of terminal buds.

Leaves

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.

blade elliptic or oblong to ovate or obovate, (25-)40-50(-85) × (18-)20-30(-50) mm, base rounded or shallowly cordate, margins entire or toothed to sublobate, secondary veins 8 to 10 on each side, somewhat branching, apex broadly rounded to acute;

surfaces abaxially yellowish or grayish, densely stellate with velvety hairs, adaxially green, sparsely soft-pubescent with prominent, spreading, stellate hairs, felty to touch, secondary veins somewhat prominent on both surfaces, even under dense tomentum.

Acorns

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.

1-3 on tomentose peduncle 15-35(-60) mm;

cup hemispheric, 7-10 mm deep × 10-15 mm wide, enclosing 1/2 nut, scales proximally thickened, distally appressed, densely gray-puberulent, tips reddish, ultimately glabrate;

nut ovoid, 14-18 × 10-12 mm, puberulent, eventually glabrate.

Cotyledons

connate.

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.

Quercus incana

Quercus chihuahuensis

Phenology Flowering spring. Flowering spring.
Habitat Well-drained sandy soils of barrens, hammocks, dunes, and upland ridges Oak and pinyon-juniper woodlands, grassy hills, sometimes extending into dry thorn scrub and bursera woodland (Mexico)
Elevation 0-250 m (0-800 ft) 400-2000 m (1300-6600 ft)
Distribution
from FNA
AL; AR; FL; GA; LA; MS; NC; OK; SC; TX; VA
[WildflowerSearch map]
[BONAP county map]
from FNA
TX; Mexico (Chihuahua, Sonora, Zacatecas, and San Luis Potosí)
[WildflowerSearch map]
[BONAP county map]
Discussion

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.)

Quercus chihuahuensis is a distinctive species throughout its range, mostly in dry montane western Mexico; it occurs in the United States only as putative hybrids with Q. grisea (the Eagle and Quitman mountains) and Q. arizonica (Hueco Tanks) in Texas.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 3. FNA vol. 3.
Parent taxa Fagaceae > Quercus > sect. Lobatae Fagaceae > Quercus > sect. Quercus
Sibling taxa
Q. acerifolia, Q. agrifolia, Q. ajoensis, Q. alba, Q. arizonica, Q. arkansana, Q. austrina, Q. berberidifolia, Q. bicolor, Q. boyntonii, Q. buckleyi, Q. carmenensis, Q. chapmanii, Q. chihuahuensis, Q. chrysolepis, Q. coccinea, Q. cornelius-mulleri, Q. depressipes, Q. douglasii, Q. dumosa, Q. durata, Q. ellipsoidalis, Q. emoryi, Q. engelmannii, Q. falcata, Q. fusiformis, Q. gambelii, Q. garryana, Q. geminata, Q. georgiana, Q. graciliformis, Q. gravesii, Q. grisea, Q. havardii, Q. hemisphaerica, Q. hinckleyi, Q. hypoleucoides, Q. ilicifolia, Q. imbricaria, Q. inopina, Q. intricata, Q. john-tuckeri, Q. kelloggii, Q. laceyi, Q. laevis, Q. laurifolia, Q. lobata, Q. lyrata, Q. macrocarpa, Q. margarettae, Q. marilandica, Q. michauxii, Q. minima, Q. mohriana, Q. montana, Q. muehlenbergii, Q. myrtifolia, Q. nigra, Q. oblongifolia, Q. oglethorpensis, Q. pacifica, Q. pagoda, Q. palmeri, Q. palustris, Q. phellos, Q. polymorpha, Q. prinoides, Q. pumila, Q. pungens, Q. robur, Q. robusta, Q. rubra, Q. rugosa, Q. sadleriana, Q. shumardii, Q. similis, Q. sinuata, Q. stellata, Q. tardifolia, Q. texana, Q. tomentella, Q. toumeyi, Q. turbinella, Q. vacciniifolia, Q. vaseyana, Q. velutina, Q. viminea, Q. virginiana, Q. wislizenii
Q. acerifolia, Q. agrifolia, Q. ajoensis, Q. alba, Q. arizonica, Q. arkansana, Q. austrina, Q. berberidifolia, Q. bicolor, Q. boyntonii, Q. buckleyi, Q. carmenensis, Q. chapmanii, Q. chrysolepis, Q. coccinea, Q. cornelius-mulleri, Q. depressipes, Q. douglasii, Q. dumosa, Q. durata, Q. ellipsoidalis, Q. emoryi, Q. engelmannii, Q. falcata, Q. fusiformis, Q. gambelii, Q. garryana, Q. geminata, Q. georgiana, Q. graciliformis, Q. gravesii, Q. grisea, Q. havardii, Q. hemisphaerica, Q. hinckleyi, Q. hypoleucoides, Q. ilicifolia, Q. imbricaria, Q. incana, Q. inopina, Q. intricata, Q. john-tuckeri, Q. kelloggii, Q. laceyi, Q. laevis, Q. laurifolia, Q. lobata, Q. lyrata, Q. macrocarpa, Q. margarettae, Q. marilandica, Q. michauxii, Q. minima, Q. mohriana, Q. montana, Q. muehlenbergii, Q. myrtifolia, Q. nigra, Q. oblongifolia, Q. oglethorpensis, Q. pacifica, Q. pagoda, Q. palmeri, Q. palustris, Q. phellos, Q. polymorpha, Q. prinoides, Q. pumila, Q. pungens, Q. robur, Q. robusta, Q. rubra, Q. rugosa, Q. sadleriana, Q. shumardii, Q. similis, Q. sinuata, Q. stellata, Q. tardifolia, Q. texana, Q. tomentella, Q. toumeyi, Q. turbinella, Q. vacciniifolia, Q. vaseyana, Q. velutina, Q. viminea, Q. virginiana, Q. wislizenii
Synonyms Q. cinerea Q. infralutea, Q. jaliscensis, Q. santaclarensis
Name authority W. Bartram: Travels Carolina, 378. (1791) Trelease: Mem. Natl. Acad. Sci. 20: 85. (1924)
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