Quercus robur |
Quercus carmenensis |
|
---|---|---|
British oak, chêne pédoncule, English oak, French oak, pedunculate oak |
Mexican oak |
|
Habit | Trees, deciduous, to 30 m. Bark light gray, scaly. | Shrubs or trees, deciduous, shrubs 0.5-2 m, rhizomatous, trees (on better sites) to 12 m, trunk 0.75 m diam. |
Bark | light gray, checkered or furrowed. |
|
Twigs | brown, 2-3 mm diam., glabrous. |
often strikingly red, 1-1.5 mm diam., sparingly (rarely densely) stellate-pubescent, somewhat glabrescent and gray 2d year. |
Buds | dark brown, ovoid, distally obtuse, 2-3 mm, glabrous. |
light brown, nearly round, 1-1.5 mm, indumentum similar to twigs. |
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 obovate or narrowly obovate, (20-)30-50 × 10-30 mm, thin to moderately leathery, base cuneate to rounded, margins shallowly and irregularly lobed or coarsely toothed in distal 1/2, rarely subentire, teeth mucronate, secondary veins 9-12 on each side, branching or passing directly to teeth, apex acute, sometimes broadly rounded; surfaces abaxially light green or yellow-green, prominently pubescent with minute, erect velvety hairs, adaxially surfaces dark green, sparsely and minutely stellate-pubescent. |
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 short-pedunculate (immature); cup (mature) unknown; scales (immature) light brown, tip acute, canescent. |
Cotyledons | distinct. |
unknown. |
Nut | unknown. |
|
2n | = 24. |
|
Quercus robur |
Quercus carmenensis |
|
Phenology | Flowering spring. | |
Habitat | Roadsides, pastures, forest margins and woodlands | Shrublands and woodlands on limestone |
Elevation | 0-1000 m (0-3300 ft) | 2200-2500 m (7200-8200 ft) |
Distribution |
BC; NB; NS; PE [Introduced from Europe]
|
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.) |
Of conservation concern. Shrublands and woodlands on limestone; of conservation concern; 2200-2500 m; Tex.; Mexico (Coahuila). Quercus carmenensis is known in the United States from only one collection from the Chisos Mountains, Texas; otherwise, it is known in the Sierra del Carmen region, Coahuila, Mexico. (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) | C. H. Muller: Amer. Midl. Naturalist 18: 847. (1937) |
Web links |
|