Quercus robur |
Quercus mohriana |
|
---|---|---|
British oak, chêne pédoncule, English oak, French oak, pedunculate oak |
Mohr oak, Mohr's oak, Mohr's shinoak |
|
Habit | Trees, deciduous, to 30 m. Bark light gray, scaly. | Shrubs or trees, evergreen or deciduous, shrubs erect, rhizomatous, trees small, 0.5-3 m. Bark pale, rough and deeply furrowed. |
Twigs | brown, 2-3 mm diam., glabrous. |
yellowish or whitish, 1-2 mm diam., felty-tomentose. |
Buds | dark brown, ovoid, distally obtuse, 2-3 mm, glabrous. |
dark red-brown, round-ovoid, 2 mm, glabrous, occasionally puberulent on outer scales, not subtended by persistent, hairy, subulate stipules. |
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 usually strongly bicolored, oblong or elliptic, (15-)30-50(-80) × (10-)20-30(-35) mm, leathery, base rounded, rarely cuneate or cordulate, margins entire or toothed or denticulate, undulate or flat, secondary veins 8-9 on each side, apex rounded or acute; surfaces abaxially densely gray- or white-tomentose with semi-erect curly, stellate hairs, secondary veins rather prominently raised, adaxially dark or dull green, lustrous or somewhat glaucous, with minute, scattered, semi-erect or appressed-stellate, (4-)6 or many rayed hairs, not felty to touch, secondary veins slightly raised or prominent within depressions. |
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. |
solitary or paired, subsessile or peduncle sometimes 10-15 mm, tomentose like twigs; cup shallowly to very deeply cup-shaped, 5-12 mm deep × 8-18 mm wide, enclosing 1/2 nut, base rounded or flat, margin thin, scales triangular-ovate to oblong, proximal scales coarsely tuberculate and canescent-tomentose, distal ones usually elongate and narrowed, tips appressed, reddish, thin, nearly glabrous; nut light brown, ellipsoid to ovoid, 8-15 × 5-12 mm. |
Cotyledons | distinct. |
connate. |
2n | = 24. |
|
Quercus robur |
Quercus mohriana |
|
Phenology | Flowering spring. | Flowering spring. |
Habitat | Roadsides, pastures, forest margins and woodlands | Limestone hills and slopes, calcareous substrates |
Elevation | 0-1000 m (0-3300 ft) | 600-2500 m (2000-8200 ft) |
Distribution |
BC; NB; NS; PE [Introduced from Europe]
|
NM; OK; TX; Mexico (Coahuila)
|
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.) |
Putative hybrids between Quercus mohriana Buckley and Q. grisea Liebmann are problematic and highly polymorphic. They are restricted to zones of contact between limestone, the preferred habitat of Q. mohriana, and igneous substrates, the preferred habitat of Q. grisea, or sometimes on dolomite, in western Texas. (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. pedunculata | |
Name authority | Linnaeus: Sp. Pl. 2: 996. (1753) | Buckley: in Rydberg, Bull. New York Bot. Gard. 2: 219. (1901) |
Web links |
|