Quercus pumila |
Quercus viminea |
|
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runner oak, running oak |
Mexican willow oak, Sonoran oak |
|
Habit | Shrubs, deciduous or tardily deciduous, to 1 m. Bark gray to dark brown. | Trees, evergreen or drought-deciduous, to 10 m. Twigs brown to dark reddish brown, 2-3 mm diam., sparsely to uniformly pubescent. |
Twigs | gray-brown to reddish brown, 1-2 mm diam., sparsely to uniformly pubescent. |
|
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 narrowly lanceolate, widest at or proximal to middle, 35-60[-150] × 7-10 mm, base usually rounded or obtuse, often oblique, occasionally somewhat cordate, margins entire with 1 apical awn, apex acute to acuminate; surfaces abaxially glabrous or with prominent tufts of tomentum near base of blade, adaxially glabrous or with pubescence along midrib and scattered on blade. |
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. |
(not known within our range) biennial; cup cup-shaped, 5-8 mm high × 8-10 mm wide, covering ca. 1/3 nut, inner surface pubescent, scales with appressed, obtuse tips; nut ovoid, 9-15 × 7-10 mm. |
Terminal | buds brown to red-brown, ovoid, 2.5-4.5 mm, glabrous or with ciliate scale margins. |
buds brown to reddish brown, acutely ovoid, 1.5-2.5 mm, glabrous. |
Quercus pumila |
Quercus viminea |
|
Phenology | Flowering spring. | Flowering spring or summer. |
Habitat | Dry sandy soils of savannahs, low ridges and oak-pine scrub, occasionally at margins of poorly drained sites | Habitat not specified |
Elevation | 0-100 m (0-300 ft) | 1500 m (4900 ft) |
Distribution |
AL; FL; GA; MS; NC; SC
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AZ; Mexico (Chihuahua, Sonora, and southward)
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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.) |
As with many of the Madrean counterparts of the oak flora, in very dry years trees progressively lose their leaves through the long dry spring and may become virtually leafless by the time the rains come in early summer (R. W. Spellenberg, pers. comm.). In the flora, Quercus viminea is known from a single sterile specimen collected at Red Mountain, Santa Cruz County, Arizona. Recent attempts to find the taxon at this site have been fruitless. The Arizona specimen is similar to specimens from northern Mexico that have small, usually entire, narrowly lanceolate leaves with short petioles. These northern forms appear to grade clinally into larger-leaved southern forms that fit the general description of Q. bolanyosensis Trelease. (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. Lobatae |
Sibling taxa | ||
Name authority | Walter: Fl. Carol., 234. (1788) | Trelease: Mem. Natl. Acad. Sci. 20: 123, plate 222. (1924) |
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