Quercus cornelius-mulleri |
Quercus rugosa |
|
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desert scrub oak, muller oak, muller's oak |
netleaf oak |
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Habit | Shrubs, evergreen or subevergreen, densely branched, 1-2(-3) m. Bark gray, scaly. | Shrubs or trees, evergreen, usually moderate-sized, rarely large. |
Bark | light or dark brown, scaly. |
|
Twigs | gray, yellowish, or brownish, 1-1.5 mm diam., densely tomentulose, rarely glabrate. |
brown, turning gray with age, 1-2 mm diam., tomentose to tomentulose, variously glabrate or persistently pubescent. |
Buds | dull brown, ovoid, 2.5-3 mm, glabrous except for margins of scales. |
brown, ovoid, 2-4 mm, apex obtuse, sparsely pubescent or eventually glabrate. |
Leaves | 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. |
blade broadly obovate or panduriform to orbiculate or elliptic, rarely narrowly obovate, usually cupped, strongly concave proximally, sometimes planar, to 100 × 70 mm, stiff, leathery, base deeply or shallowly cordate, margins usually somewhat revolute, cartilaginously thickened, undulately crisped or flat with inconspicuous or coarse mucronate teeth near apex, secondary veins 8-10(-12) on each side, branched, apex broadly rounded, rarely subacute; surfaces abaxially dull, glaucous, or densely brownish tomentose, becoming nearly glabrate or pubescence persistent, especially about midribs, secondary veins very prominently raised, reticulate, adaxially dark green, lustrous, sparsely stellate-pubescent especially about base of midrib, secondary veins impressed. |
Acorns | 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. |
1-3 or more on slender axillary peduncle 30-60 mm; cup deeply cup-shaped to saucer-shaped, to 9 mm deep × 15 mm wide, enclosing to 1/2 nut, scales loosely appressed, characteristically somewhat spreading, brown, ovate, tuberculate-thickened or only slightly so, tomentose or obscurely tomentulose; nut light brown, ovoid to elliptic, to 20 × 15 mm, glabrous or minutely villous. |
Cotyledons | distinct. |
distinct, often reddish or purple. |
Quercus cornelius-mulleri |
Quercus rugosa |
|
Phenology | Flowering early spring. | Flowering early–late spring. |
Habitat | Open chaparral, pinyon and juniper woodlands, desert margins, often on loose granitic soils | Wooded slopes |
Elevation | 1000-1800 m (3300-5900 ft) | 2000-2500 m (6600-8200 ft) |
Distribution |
CA; Mexico (Baja California)
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AZ; NM; TX; Mexico; Central America (Guatemala)
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Discussion | 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.) |
Quercus rugosa occurs on wooded slopes at high elevations in trans-Pecos Texas, southern New Mexico, and Arizona, and throughout most of the mesic montane parts of Mexico, south to Guatemala. (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. ariifolia, Q. diversicolor, Q. durangensis, Q. reticulata, Q. rhodophlebia, Q. vellifera | |
Name authority | Nixon & K. P. Steele: Madroño 28: 210. (1981) | Nee.: Anales Ci. Nat. 3: 275. (1801) |
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