Quercus robur |
Quercus wislizenii |
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British oak, chêne pédoncule, English oak, French oak, pedunculate oak |
interior live oak, Sierra live oak |
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Habit | Trees, deciduous, to 30 m. Bark light gray, scaly. | Trees or shrubs, evergreen, to 22 m. Bark nearly black, deeply furrowed with broad scaly ridges. |
Twigs | brown, 2-3 mm diam., glabrous. |
brown to red-brown, 1.5-3 mm diam., glabrous or sparsely pubescent. |
Buds | dark brown, ovoid, distally obtuse, 2-3 mm, glabrous. |
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Leaves | blade obovate to narrowly elliptic or narrowly obovate (some cultivars oblanceolate), (50-)70-150(-200) × (20-)35-85(-100) mm, base strongly cordate, often minutely revolute or folded, margins moderately to deeply lobed, lobes rounded or retuse distally, sinuses extending 1/3-7/8 distance to midrib, secondary veins arched, divergent, (3-)5-7 on each side, apex broadly rounded; surfaces abaxially light green, glabrous or sparsely pubescent, glabrous at maturity, adaxially deep green to light green or gray, dull or glossy. |
blade circular to oblong, usually ovate, planar, 25-70 × 20-50 mm, base obtuse to cordate, margins entire or spinose with up to 16 awns, apex acute to rounded; surfaces abaxially and adaxially glabrous, veins little raised on either surface. |
Acorns | 1-3, on very thin (1-2 mm diam.), flexuous peduncle (25-)35-65(-100) mm; cup hemispheric to deeply goblet-shaped, enclosing 1/4-1/2 nut or more, scales closely appressed, often in concentric rows, finely grayish tomentose; nut brown, ovoid, oblong, or cylindric, 15-30(-35) × 12-20 mm, glabrous. |
biennial; cup deeply and narrowly cup-shaped or U-shaped, 9-19 mm high × 7-18 mm wide, covering 1/3-1/2(-2/3) nut, outer surface glabrous to sparsely puberulent, inner surface glabrous or pubescent on innermost 1/3, occasionally uniformly pubescent, scales acute, tips loose; nut narrowly conic or ovoid to narrowly oblong, 21-44 × 8-14 mm, glabrous, scar diam. 2.5-7.5 mm. |
Cotyledons | distinct. |
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Terminal | buds light chestnut brown to dark reddish brown, ovoid to conic, 3-9 mm, glabrous or with tuft of minute hairs at apex. |
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2n | = 24. |
= 24. |
Quercus robur |
Quercus wislizenii |
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Phenology | Flowering spring. | Flowering late spring. |
Habitat | Roadsides, pastures, forest margins and woodlands | Valleys, slopes, and sand chaparral |
Elevation | 0-1000 m (0-3300 ft) | 300-1900 m (1000-6200 ft) |
Distribution |
BC; NB; NS; PE [Introduced from Europe]
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CA
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Discussion | Quercus robur is one of the oaks most commonly cultivated in temperate and subtropical parts of the world. In North America it is most commonly seen in the eastern and northwestern parts of the United States and and in southeastern and southwestern Canada, where it tolerates a wide array of conditions and is extremely hardy. In Washington, New Brunswick, and Nova Scotia, apparently reproducing populations persist in the wild. Elsewhere, although actual naturalization appears to be rare, Q. robur should be expected to persist around old homesites and other places of cultivation. Quercus robur most closely resembles our native species Q. alba in leaf form. In contrast with Q. alba, which has relatively long petioles (longer than 10 mm), acute leaf bases, and subsessile fruit (rarely on peduncles to 25 mm), Q. robur is easily distinguished by its shorter petioles (less than 10 mm), cordate, almost clasping, leaf bases, and fruit on long (more than 35 mm), thin peduncles. Quercus robur is one of the oaks most widely celebrated in literature; it has wood of exceptionally high quality for the manufacture of furniture, and it previously was the most important wood used in the manufacture of wooden sailing vessels in Europe. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Shrubs with oval leaves 25-38 mm and margins entire or deeply lobed-dentate may be treated as Quercus wislizenii var. frutescens. J. M. Tucker (1993) treated Q. parvula as a distinct species, distinguished from Q. wislizenii by its larger leaves (30-90 versus 20-50 mm), by the dull, olive-green, abaxial leaf surface (versus shiny, yellow-green), and by nuts that are abruptly tapered proximal to the middle (versus gradually tapered). Tucker recognized two varieties of Quercus parvula: Q. parvula var. parvula is a shrub of 1-3 m and Q. parvula var. shrevei is a tree less than 17 m. S. K. Langer (1993) recognized a third variety, Q. parvula var. tamalpaisensis,based on several small populations on or near Mount Tamalpais, differentiated primarily by having larger leaves (50-160 × 20-60 mm) with attenuate-dentate margins. Quercus wislizenii reportedly hybridizes with Q. agrifolia and Q. kelloggii (W. B. Brophy and D. R. Parnell 1974). (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. Lobatae |
Sibling taxa | ||
Synonyms | Q. pedunculata | Q. parvula, Q. parvula var. shrevei, Q. parvula var. tamalpaisensis, Q. wislizenii var. frutescens |
Name authority | Linnaeus: Sp. Pl. 2: 996. (1753) | A. de Candolle: in A. P. de Candolle and A. L. P. de Candolle, Prodr. 16(2): 67. (1864) |
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