Flora of North America species comparison

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Quercus robur

Quercus inopina

British oak, chêne pédoncule, English oak, French oak, pedunculate oak

sandhill oak
Habit Trees, deciduous, to 30 m. Bark light gray, scaly. Shrubs, evergreen, to 5 m. Bark gray.
Twigs

brown, 2-3 mm diam., glabrous.

light to dark purplish brown, (1.5-)2-3(-4) mm diam., glabrate to sparsely pubescent, especially at apex.
Buds

dark brown, ovoid, distally obtuse, 2-3 mm, glabrous.

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 ovate or elliptic to obovate, occasionally spatulate, (25-)45-85 × (15-)25-45 mm, base acute to rounded or cordate, margins entire, strongly revolute, with 1 apical awn, apex obtuse or rounded;

surfaces abaxially yellow-scurfy, occasionally somewhat pubescent, rarely glabrous, adaxially distinctly convex, rugose, glabrous or with scattered hairs, especially along midrib and at base.
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 cup-shaped to bowl-shaped, 6-8 mm high × 10-15 mm wide, covering 1/3-1/2 nut, outer surface puberulent, inner surface half to fully pubescent, scale tips tightly appressed, acute;

nut ovoid to broadly ellipsoid, 10-14 × 9-13 mm, glabrate, scar diam. 4.5-8 mm.
Cotyledons

distinct.

Terminal

buds dark purplish brown, ovoid to subconic, 2-6 mm, noticeably 5-angled in cross section, glabrous to tawny strigose on apical 1/3.
2n

= 24.

Quercus robur

Quercus inopina
Phenology Flowering spring. Flowering spring.
Habitat Roadsides, pastures, forest margins and woodlands On deep white "sugar" sands of low sandhill ridges, scrub communities, and flat upland terraces
Elevation 0-1000 m (0-3300 ft) 0-50 m (0-200 ft)
Distribution
from FNA
BC; NB; NS; PE [Introduced from Europe]
[WildflowerSearch map]
[BONAP county map]
from FNA
FL
[WildflowerSearch map]
[BONAP county map]
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.)

Quercus inopina occurs from Orange County, Florida, southwest to Manatee County and south to Martin County. It flowers one to two weeks later than Q. myrtifolia (A. F. Johnson and W. G. Abrahamson 1982).

The leaves of this species often have numerous small black dots on the adaxial surface. These are ascocarps (the sexual fruiting bodies of ascomycete fungi) of the genus Asterina (D. M. Hunt, pers. comm).

Although no hybrids have been formally described, evidence of hybridization of Quercus inopina with Q. hemisphaerica, Q. laevis, and Q. myrtifolia has been reported (D. M. Hunt 1989).

(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
Q. acerifolia, Q. agrifolia, Q. ajoensis, Q. alba, Q. arizonica, Q. arkansana, Q. austrina, Q. berberidifolia, Q. bicolor, Q. boyntonii, Q. buckleyi, Q. carmenensis, Q. chapmanii, Q. chihuahuensis, Q. chrysolepis, Q. coccinea, Q. cornelius-mulleri, Q. depressipes, Q. douglasii, Q. dumosa, Q. durata, Q. ellipsoidalis, Q. emoryi, Q. engelmannii, Q. falcata, Q. fusiformis, Q. gambelii, Q. garryana, Q. geminata, Q. georgiana, Q. graciliformis, Q. gravesii, Q. grisea, Q. havardii, Q. hemisphaerica, Q. hinckleyi, Q. hypoleucoides, Q. ilicifolia, Q. imbricaria, Q. incana, Q. inopina, Q. intricata, Q. john-tuckeri, Q. kelloggii, Q. laceyi, Q. laevis, Q. laurifolia, Q. lobata, Q. lyrata, Q. macrocarpa, Q. margarettae, Q. marilandica, Q. michauxii, Q. minima, Q. mohriana, Q. montana, Q. muehlenbergii, Q. myrtifolia, Q. nigra, Q. oblongifolia, Q. oglethorpensis, Q. pacifica, Q. pagoda, Q. palmeri, Q. palustris, Q. phellos, Q. polymorpha, Q. prinoides, Q. pumila, Q. pungens, Q. robusta, Q. rubra, Q. rugosa, Q. sadleriana, Q. shumardii, Q. similis, Q. sinuata, Q. stellata, Q. tardifolia, Q. texana, Q. tomentella, Q. toumeyi, Q. turbinella, Q. vacciniifolia, Q. vaseyana, Q. velutina, Q. viminea, Q. virginiana, Q. wislizenii
Q. acerifolia, Q. agrifolia, Q. ajoensis, Q. alba, Q. arizonica, Q. arkansana, Q. austrina, Q. berberidifolia, Q. bicolor, Q. boyntonii, Q. buckleyi, Q. carmenensis, Q. chapmanii, Q. chihuahuensis, Q. chrysolepis, Q. coccinea, Q. cornelius-mulleri, Q. depressipes, Q. douglasii, Q. dumosa, Q. durata, Q. ellipsoidalis, Q. emoryi, Q. engelmannii, Q. falcata, Q. fusiformis, Q. gambelii, Q. garryana, Q. geminata, Q. georgiana, Q. graciliformis, Q. gravesii, Q. grisea, Q. havardii, Q. hemisphaerica, Q. hinckleyi, Q. hypoleucoides, Q. ilicifolia, Q. imbricaria, Q. incana, Q. intricata, Q. john-tuckeri, Q. kelloggii, Q. laceyi, Q. laevis, Q. laurifolia, Q. lobata, Q. lyrata, Q. macrocarpa, Q. margarettae, Q. marilandica, Q. michauxii, Q. minima, Q. mohriana, Q. montana, Q. muehlenbergii, Q. myrtifolia, Q. nigra, Q. oblongifolia, Q. oglethorpensis, Q. pacifica, Q. pagoda, Q. palmeri, Q. palustris, Q. phellos, Q. polymorpha, Q. prinoides, Q. pumila, Q. pungens, Q. robur, Q. robusta, Q. rubra, Q. rugosa, Q. sadleriana, Q. shumardii, Q. similis, Q. sinuata, Q. stellata, Q. tardifolia, Q. texana, Q. tomentella, Q. toumeyi, Q. turbinella, Q. vacciniifolia, Q. vaseyana, Q. velutina, Q. viminea, Q. virginiana, Q. wislizenii
Synonyms Q. pedunculata
Name authority Linnaeus: Sp. Pl. 2: 996. (1753) Ashe: Rhodora 31: 79. (1929)
Web links 
Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).



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