Quercus nigra |
Quercus oglethorpensis |
|
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chêne gris, water oak |
Oglethorpe oak |
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Habit | Trees, deciduous or tardily deciduous, to 30 m. Bark grayish black, fissures irregular, shallow, inner bark pinkish. | Trees, deciduous, to 18(-25) m. Bark light gray or whitish, scaly. |
Twigs | dark red-brown, 1.5-2.5 mm diam., glabrous. |
brownish red, ca. 1 mm diam., sparsely pubescent, glabrate with age. |
Buds | reddish brown, globose, to 2-2.5 mm, sparsely pubescent or glabrous. |
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Leaves | blade distinctly obtrullate, rarely elliptic or merely obovate, widest near apex, 30-120(-160) × 15-60(-70) mm, base attenuate or cuneate, rarely rounded, margins entire with 1 apical awn or with 2-3 shallow lobes and 2-5 awns (leaves on juvenile or 2d-flush growth may be deeply lobed with more awns), apex obtuse to blunt or rounded; surfaces abaxially glabrous except for minute or conspicuous axillary tufts of tomentum, veins rarely raised, adaxially glabrous with secondary veins somewhat impressed. |
blade narrowly elliptic or oblanceolate, ± planar, not strongly convexly cupped, 50-150 × 20-45 mm, base cuneate to cordate, margins entire or on vigorous shoots sometimes sinuate near apex, secondary veins 3-5 on each side, apex rounded, obtuse or broadly acute; surfaces abaxially yellowish green, covered with persistent velvety branched hairs, adaxially dark green, dull or glossy, sparsely stellate, often somewhat sandpapery with harsh hairs. |
Acorns | biennial; cup saucer-shaped, 2.5-5.5 mm high × 10-18 mm wide, covering 1/4 nut or less, outer surface puberulent, inner surface sparsely to uniformly pubescent, scale tips tightly appressed, acute; nut broadly ovoid, 9.5-14 × 9.5-14.5 mm, often faintly striate, glabrate, scar diam. 6-11.5 mm. |
1-2, subsessile or on peduncle to 7 mm; cup turbinate, somewhat constricted proximally, 8 mm deep × 10 mm wide, enclosing 1/3 nut or more, scales closely appressed, finely tan-pubescent; nut gray brown, ovoid, 9-11 × (5-)7-9 mm, finely puberulent. |
Cotyledons | distinct. |
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Terminal | buds reddish brown, ovoid, 3-6.5 mm, puberulent throughout, occasionally densely pubescent on apical 2/3. |
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Quercus nigra |
Quercus oglethorpensis |
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Phenology | Flowering spring. | Flowering spring. |
Habitat | Mesic alluvial and lowland sites, also barrens, dunes, hammocks, and low ridges to steep slopes | Alluvial flatwoods and streamsides in rich woods, low pastures, and edge of bottomland forests |
Elevation | 0-450 m (0-1500 ft) | 0-200 m (0-700 ft) |
Distribution |
AL; AR; DE; FL; GA; KY; LA; MD; MO; MS; NC; NJ; OK; SC; TN; TX; VA
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GA; LA; MS; SC |
Discussion | Typically on mesic alluvial and lowland sites, Quercus nigra also occurs on a wide variety of soil types and in a diversity of habitats. Trees with 3-lobed leaves with attenuate bases have been recognized as Quercus nigra var. tridentifera Sargent. Quercus nigra reportedly hybridizes with Q. falcata (= Q. ×garlandensis E. J. Palmer), Q. incana, Q. laevis (= Q. ×walteriana Ashe), Q. marilandica (= Q. ×sterilis Trelease), Q. phellos (= Q. ×capesii W. Wolf), Q. shumardii (= Q. ×neopalmeri Sudworth), and Q. velutina (Q. ×demarei Ashe). In addition, D. M. Hunt (1989) cited evidence of hybridization also with Q. arkansana, Q. georgiana, Q. hemisphaerica, Q. laurifolia, Q. myrtifolia, Q. palustris, Q. rubra, and Q. texana. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. Since its original discovery in 1940 in Oglethorpe County, Georgia, Quercus oglethorpensis has been found to be more common locally near the type site in Georgia and South Carolina than originally thought. It remains one of the least-known oak species of the southeastern United States. Quercus oglethorpensis is one of our most distinctive eastern oaks, easily recognized by its narrow, entire, abaxially felty leaves. (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. Quercus |
Sibling taxa | ||
Synonyms | Q. nana, Q. nigra var. tridentifera, Q. uliginosa | |
Name authority | Linnaeus: Sp. Pl. 2: 995. (1753) | Duncan: Amer. Midl. Naturalist 24: 755. (1940) |
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