Quercus ellipsoidalis |
Quercus cornelius-mulleri |
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Hill's oak, Jack oak, northern pin oak |
desert scrub oak, muller oak, muller's oak |
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Habit | Trees, deciduous, to 20 m; lower trunk often with stubs of dead branches. | Shrubs, evergreen or subevergreen, densely branched, 1-2(-3) m. Bark gray, scaly. |
Bark | dark gray-brown, shallowly fissured, inner bark orangish. |
|
Twigs | dark reddish brown, (1-)1.5-3 mm diam., glabrous. |
gray, yellowish, or brownish, 1-1.5 mm diam., densely tomentulose, rarely glabrate. |
Buds | dull brown, ovoid, 2.5-3 mm, glabrous except for margins of scales. |
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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 strongly bicolored, ovate to oblong or narrowly obovate, 15-35 ×10-20 mm, rather thick and leathery, base cuneate or attenuate-rounded, margins entire or irregularly, shallowly toothed, teeth mucronate, rarely spinose, secondary veins 6-7 on each side, apex rounded or acute; surfaces abaxially whitish, densely covered with minute, compact, appressed, (8-)10-14(-16)-rayed stellate hairs less than 0.2 mm diam. (lateral fusion of rays visible under high magnification), without glandular seriate hairs, adaxially dull, light green, grayish, or yellowish green, with scattered, appressed-stellate hairs to 0.2 mm diam. |
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 clustered, subsessile; cup deeply cup-shaped or turbinate, to 5-13 mm deep × 12-20 mm wide, scales whitish or cream, strongly tuberculate especially near base of cup; nut dark brown, fusiform or cylyndric, 20-30 × 10-30 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 cornelius-mulleri |
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Phenology | Flowering spring. | Flowering early spring. |
Habitat | Dry sandy sites, rarely on moderately mesic slopes or uplands | Open chaparral, pinyon and juniper woodlands, desert margins, often on loose granitic soils |
Elevation | 150-500 m (500-1600 ft) | 1000-1800 m (3300-5900 ft) |
Distribution |
IA; IL; IN; MI; MN; OH; WI; ON
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CA; Mexico (Baja California)
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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.) |
Quercus cornelius-mulleri is easily distinguished from other California scrub oaks by the strongly bicolored leaves, dense minute tomentum of the abaxial leaf surface, and large acute acorns in deep tuberculate cups. Of greater difficulty are swarms of putative hybrids with Q. engelmannii, sometimes referred to as Q. ×acutidens. In Joshua Tree National Monument a lone tree and several shrubs appear to be hybrids and backcrosses between Quercus cornelius-mulleri and Q. lobata. This tree is the basis of Quercus ×munzii J. M. Tucker. (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 | |
Name authority | E. J. Hill: Bot. Gaz. 27: 204, plates 2, 3. (1899) | Nixon & K. P. Steele: Madroño 28: 210. (1981) |
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