Flora of North America species comparison

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Quercus john-tuckeri

Quercus gambelii

desert scrub oak, Tucker oak, Tucker's oak

Gambel oak
Habit Shrubs, subevergreen or evergreen, 1-3(-5) m. Bark light gray or brown, scaly. Shrubs or trees, deciduous, shrubs sometimes clumped and spreading, trees small or moderately large.
Bark

gray or brown, scaly.
Twigs

yellowish or dingy gray, 1-1.5(-2) mm diam., densely tomentulose.

brown or reddish brown with few, inconspicuous lenticels, 1.5-2.5 mm diam., glabrous or stellate-pubescent.
Buds

brown, ovoid or globose, 1.5-2(-3) mm, glabrous except for ciliate margins of scales;

proximal scales often yellowish puberulent.

brown, ovoid, ca. 3 mm, apex acute or obtuse, sparsely pubescent, becoming glabrate.
Leaves

blade unicolored, elliptic or obovate, (10-)15-30(-40) × (8-)10-15(-20) mm, thick and leathery, often brittle, base truncate or rounded-attenuate, rarely subcordate, margins irregularly spinose-toothed, occasionally shallowly lobate, secondary veins (3-)4-7, often some veins branching near margin and passing into more than 1 tooth, apex acute or rounded;

surfaces abaxially waxy grayish, light green, or yellowish, sparse to moderately dense (8-)10-12-rayed, (loosely) appressed-stellate hairs, often 0.2-0.5 mm diam., and sparse to crowded, yellowish, glandular hairs, adaxially dull grayish, with stellate hairs, similar to abaxial surface.

blade elliptic to obovate or oblong, deeply to shallowly 4-6-lobed, (40-)80-120(-160) × (25-)40-60(-100) mm, membranous, base truncate to cuneate, margins entire or coarsely toothed, lobes oblong, rounded or subacute, sinuses acute or narrowly rounded at base, reaching more than 1/2 distance to midrib, secondary veins 4-6 on each side, each passing into lobe, branched, apex broadly rounded;

surfaces abaxially dull green, sometimes glaucous, densely velvety with erect 4-6-rayed hairs, sometimes glabrate or persistently villous only near midribs, secondary veins prominent, adaxially lustrous dark green, appearing glabrate, microscopically pubescent, secondary veins slightly raised.
Acorns

solitary or paired, subsessile;

cup cup-shaped or obconic to hemispheric, 5-7 mm deep × 10-15 mm wide, thin, scales whitish or yellowish, moderately or scarcely tuberculate, puberulent;

nut fusiform, ovoid, or conic, 20-30 mm, apex acute.

solitary or paired, subsessile or on peduncle to 10(-30) mm;

cup deeply cup-shaped, 5-8(-17) mm deep × 7-15(-25) mm wide, enclosing 1/4-1/2 nut, base round, margin thin, scales closely appressed, ovate, markedly tuberculate, proximally gray-tomentulose;

nut light brown, ovoid to ellipsoid, (8-)12-15(-33) × 7-12(-18) mm.
Cotyledons

distinct.

distinct.

Quercus john-tuckeri

Quercus gambelii
Phenology Flowering mid-late spring.
Habitat Dry slopes, chaparral, pinyon and juniper woodlands, margins of oak woodlands and sagebrush Montane conifer, oak-maple, and higher margins of pinyon-juniper woodlands
Elevation 900-2000 m (3000-6600 ft) 1000-3030 m (3300-9900 ft)
Distribution
from FNA
CA
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; CO; NM; NV; OK; TX; UT; WY; Mexico (Chihuahua, Coahuila, and Sonora)
[WildflowerSearch map]
[BONAP county map]
Discussion

Dry slopes, chaparral, pinyon and juniper woodlands, margins of oak woodlands and sagebrush; 900-2000 m; Calif.

Endemic to California, Quercus john-tuckeri occurs from Los Angeles County northward in the interior Coast Ranges and Sierra Foothills to the northern edge of Sacramento Valley.

Quercus john-tuckeri bears some resemblance to both Q. turbinella and Q. berberidifolia. Quercus turbinella has pedunculate fruit and cordate leaf bases, however, and Q. berberidifolia has a glabrate adaxial leaf surface, substantially smaller stellate trichomes with fewer rays on the abaxial leaf surface, heavier tuberculate acorn cups, and blunt or rounded (instead of acute) acorns.

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

Numerous hybrids of Quercus gambelii with various scrub oaks have been reported, including Q. grisea and Q. turbinella. Such hybrids in general have shallowly lobed or dentate, semipersistent leaves and intermediate characteristics of pubescence and fruit between parental types. Such hybrids are usually referred to as the Quercus ×undulata complex because of widespread application of the latter name to various populations.

One population from San Juan County, Utah, with larger fruit but otherwise not differing from typical Quercus gambelii, has been recognized as Q. gambelii var. bonina Welsh. Unless other characters are found to support this segregation, the plants are best not treated as a formal taxon, particularly considering the extensive variation and hybridization associated with Q. gambelii throughout its range.

Numerous putative hybrid swarms occur throughout the range of Quercus gambelii that involve a number of suspected parental species. Most of these populations have, at one time or another, been referred to Quercus undulata Torrey. The putative hybrids have serrate or shallowly lobed leaves and considerable variation in habit, leaf pubescence, and acorn morphology. J. M. Tucker (1961, 1969, 1971) and J. M. Tucker et al. (1961) have identified the major components of the Q. undulata complex as Q. turbinella (western Utah and northwestern Arizona, and central Colorado), Q. grisea (New Mexico and southern Colorado), Q. havardii (southeastern Utah and northwestern Arizona), Q. mohriana (northeastern and southern New Mexico), Q. arizonica (central Arizona), and Q. muhlenbergii (eastern and central New Mexico). Quercus macrocarpa has been implicated as a parent of variable populations in New Mexico (J. M. Tucker and J. R. Maze 1966). Because of the complex variability in these populations, no effort has been made to treat them separately here; indeed, it would be impossible to produce usable keys if these were included as formal taxa.

Hybrids derived from Quercus gambelii and an evergreen species are often semideciduous, retaining a variable portion of green or brownish leaves over the winter.

Quercus gambelii was used medicinally by the Navaho-Ramah to alleviate postpartum pain, as a cathartic, as a ceremonial emetic, and as a life medicine (D. E. Moerman 1986).

(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
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. incana, Q. inopina, Q. intricata, 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. 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. 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. turbinella subsp. californica Q. douglasii var. gambelii, Q. gambelii var. gunnisonii, Q. lesueuri, Q. marshii, Q. novomexicana, Q. undulata var. gambelii, Q. utahensis
Name authority Nixon & C. H. Muller: Novon 4: 391. (1994) Nuttall: J. Acad. Nat. Sci. Philadelphia 1(2): 179. (1848)
Web links 
Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).



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