Quercus nigra |
Quercus gravesii |
|
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chêne gris, water oak |
Chisos red oak, Graves oak |
|
Habit | Trees, deciduous or tardily deciduous, to 30 m. Bark grayish black, fissures irregular, shallow, inner bark pinkish. | Trees, deciduous, to 13 m. Bark black, roughly furrowed. |
Twigs | dark red-brown, 1.5-2.5 mm diam., glabrous. |
light brown to dark reddish brown, (1-)1.5-2.5 mm diam., glabrous or glabrate. |
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 ovate to elliptic, 45-140 × 20-120 mm, base rounded (rarely subcordate) to obtuse or cuneate, margins with 3-5 acute lobes, 9-20 awns, apex broadly obtuse or acute to attenuate, occasionally falcate; surfaces abaxially light green or coppery green, glabrous with small axillary tufts of tomentum or pubescent along midrib and veins, adaxially shiny or glossy, glabrous except for scattered pubescence near base and along midrib. |
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. |
biennial; cup turbinate or deeply cup-shaped, 4.5-8.5 mm high × 7.5-12 mm wide, covering 1/3-1/2 nut, outer surface glabrate, inner surface glabrous to pubescent on inner 2/3, scale tips appressed, less than 4 mm, acute; nut ovoid to ellipsoid, rarely subglobose or oblong, 9-16 × 5.5-11 mm, occasionally striate, glabrous to puberulent, especially at apex, scar diam. 3-6 mm. |
Terminal | buds reddish brown, ovoid, 3-6.5 mm, puberulent throughout, occasionally densely pubescent on apical 2/3. |
buds brown or reddish brown, ovoid or ellipsoid to subconic, 2-5 mm, glabrous or with tuft of hairs at apex. |
Quercus nigra |
Quercus gravesii |
|
Phenology | Flowering spring. | Flowering spring. |
Habitat | Mesic alluvial and lowland sites, also barrens, dunes, hammocks, and low ridges to steep slopes | Davis, Glass, and Chisos mountains |
Elevation | 0-450 m (0-1500 ft) | above 1200 m (above 3900 ft) |
Distribution |
AL; AR; DE; FL; GA; KY; LA; MD; MO; MS; NC; NJ; OK; SC; TN; TX; VA
|
TX; n Mexico |
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.) |
Quercus gravesii reportedly hybridizes with Q. hypoleucoides. As noted above, forms of Q. gravesii and Q. robusta are easily confused and give the impression of belonging to a single morphologic continuum. Some authors have also used the name Quercus texana for Q. gravesii. (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. Lobatae |
Sibling taxa | ||
Synonyms | Q. nana, Q. nigra var. tridentifera, Q. uliginosa | Q. chisosensis, Q. shumardii var. microcarpa, Q. stellipila, Q. texana var. chisosensis, Q. texana var. stellapila |
Name authority | Linnaeus: Sp. Pl. 2: 995. (1753) | Sudworth: Check List For. Trees U.S., 86. (1927) |
Web links |