Quercus ellipsoidalis |
Quercus gambelii |
|
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Hill's oak, Jack oak, northern pin oak |
Gambel oak |
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Habit | Trees, deciduous, to 20 m; lower trunk often with stubs of dead branches. | Shrubs or trees, deciduous, shrubs sometimes clumped and spreading, trees small or moderately large. |
Bark | dark gray-brown, shallowly fissured, inner bark orangish. |
gray or brown, scaly. |
Twigs | dark reddish brown, (1-)1.5-3 mm diam., glabrous. |
brown or reddish brown with few, inconspicuous lenticels, 1.5-2.5 mm diam., glabrous or stellate-pubescent. |
Buds | brown, ovoid, ca. 3 mm, apex acute or obtuse, sparsely pubescent, becoming glabrate. |
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Leaves | blade elliptic, 70-130 × 50-100 mm, base obtuse to truncate, margins with 5-7 deep lobes and 15-55 awns, lobes distally expanded, sinuses usually extending more than 1/2 distance to midrib, apex acute; surfaces abaxially glabrous except for minute axillary tufts of tomentum, adaxially glossy light green, glabrous, secondary veins raised on both surfaces. |
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 | biennial; cup narrowly turbinate to deeply cup-shaped, 6-11 mm high × 10-19 mm wide, covering 1/3-1/2 nut, outer surface reddish brown, puberulent, inner surface light brown, glabrous, rarely with ring of pubescence around scar, scales with straight or slightly concave margins, tips tightly appressed, obtuse or acute; nut ellipsoid to ovoid, rarely subglobose, 10-20 × 9-15 mm, occasionally striate, glabrous, occasionally with 1 or more faint rings of fine pits at apex, scar diam. 4-8 mm. |
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. |
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Terminal | buds dark reddish brown, ovoid, 3-5 mm, often conspicuously 5-angled in cross section, usually silvery- or tawny-pubescent toward apex. |
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Quercus ellipsoidalis |
Quercus gambelii |
|
Phenology | Flowering spring. | Flowering mid-late spring. |
Habitat | Dry sandy sites, rarely on moderately mesic slopes or uplands | Montane conifer, oak-maple, and higher margins of pinyon-juniper woodlands |
Elevation | 150-500 m (500-1600 ft) | 1000-3030 m (3300-9900 ft) |
Distribution |
IA; IL; IN; MI; MN; OH; WI; ON
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AZ; CO; NM; NV; OK; TX; UT; WY; Mexico (Chihuahua, Coahuila, and Sonora)
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Discussion | In many treatments (e.g., E. G. Voss 1972+, vol. 2), Quercus ellipsoidalis is included in Q. coccinea. Variation in fruit morphology has led to recognition of several formae (W. Trelease 1919; see also R. J. Jensen 1986) and one variety (Q. ellipsoidalis var. kaposianensis, based on specimens from St. Paul, Minnesota, in which the cup tightly encloses the nut for two-thirds its length at maturity). Quercus ellipsoidalis reportedly hybridizes with Q. rubra and Q. velutina. The Menominee used Quercus ellipsoidalis medicinally to treat suppressed menses caused by cold (D. E. Moerman 1986). (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. Lobatae | Fagaceae > Quercus > sect. Quercus |
Sibling taxa | ||
Synonyms | Q. ellipsoidalis var. kaposianensis | Q. douglasii var. gambelii, Q. gambelii var. gunnisonii, Q. lesueuri, Q. marshii, Q. novomexicana, Q. undulata var. gambelii, Q. utahensis |
Name authority | E. J. Hill: Bot. Gaz. 27: 204, plates 2, 3. (1899) | Nuttall: J. Acad. Nat. Sci. Philadelphia 1(2): 179. (1848) |
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