Quercus pumila |
Quercus hinckleyi |
|
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runner oak, running oak |
Hinckley oak |
|
Habit | Shrubs, deciduous or tardily deciduous, to 1 m. Bark gray to dark brown. | Shrubs, evergreen, low, to 0.75(-1.5) m, spreading rhizomatously in thickets, intricately branched. |
Bark | gray, scaly. |
|
Twigs | gray-brown to reddish brown, 1-2 mm diam., sparsely to uniformly pubescent. |
light brown, pruinose, becoming waxy-glaucous in 2d season, 1-1.5 mm diam., glabrous or sparsely and minutely stellate-pubescent. |
Buds | minute, subrotund, 0.5-1 mm; scales reddish brown, glabrous except for ciliate margins. |
|
Leaves | blade oblong to narrowly obovate, 25-100 × 10-33 mm, base acute to rounded, margins entire, revolute, with 1 apical awn, apex acute or obtuse to rounded; surfaces abaxially uniformly gray-brown pubescent, rarely glabrate, adaxially somewhat convex, rugose, glabrous or with scattered hairs along midrib. |
blade subrotund or rotund, to 15 × 15 mm, thick, leathery, base cordate or auriculate, margins strongly crisped with 2-3 coarse, spinescent teeth on each side, cartilaginous-thickened secondary veins obscure, apex acute or obtuse, spine-tipped; surfaces abaxially blue-green, glaucous, glabrous, microscopically markedly papillose, adaxially blue-green, glaucous, glabrous, secondary veins slightly raised on both surfaces. |
Acorns | annual; cup deeply saucer-shaped to turbinate, 5-12 mm high × 10-15 mm wide, covering 1/3-1/2(-2/3) nut, outer surface pubescent, inner surface densely pubescent, scales rarely involute, often tuberculate, tips tightly appressed, acute; nut globose to ovoid or broadly oblong, 9.5-15 × 9-12 mm, glabrate, scar diam. 5-8 mm. |
solitary, subsessile or on axillary peduncle to 4 mm; cup shallow, saucer-shaped, 1-3 mm deep × 10-15 mm wide, enclosing base of nut only, margin irregularly undulate, scales closely appressed, minute, basally tuberculate-thickened, glabrous except for thin ciliate margins; nut ovoid, 10-20 × 8-12 mm, glabrous. |
Cotyledons | distinct. |
|
Terminal | buds brown to red-brown, ovoid, 2.5-4.5 mm, glabrous or with ciliate scale margins. |
|
Quercus pumila |
Quercus hinckleyi |
|
Phenology | Flowering spring. | Flowering spring. |
Habitat | Dry sandy soils of savannahs, low ridges and oak-pine scrub, occasionally at margins of poorly drained sites | On dry desert slopes |
Elevation | 0-100 m (0-300 ft) | 1150-1400 m (3800-4600 ft) |
Distribution |
AL; FL; GA; MS; NC; SC
|
TX; Mexico |
Discussion | Although no hybrid combinations have been formally proposed, D. M. Hunt (1989) has reported evidence of hybridization with Quercus hemisphaerica, Q. incana, Q. myrtifolia, and Q. phellos. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. This species is known only from two sites in the United States, El Solitario and near Shafter, Texas. The Shafter population includes some individuals with characteristics that suggest hybridization with Quercus pungens Liebmann. These plants are larger, with more pubescent twigs and leaves, and hemispheric acorn cups to 10 mm deep. Such plants have recently been collected in adjacent Mexico. Fossil evidence from packrat middens indicates Q. hinckleyi probably had a broader distribution and was a dominant shrub between 19,000 and 9500 years ago. (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 | ||
Name authority | Walter: Fl. Carol., 234. (1788) | C. H. Muller: Contr. Texas Res. Found., Bot. Stud. 1: 40. (1951) |
Web links |