Quercus nigra |
Quercus marilandica |
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chêne gris, water oak |
blackjack 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 15 m. Bark almost black, with irregular or rectangular blocks, inner bark orangish. |
Twigs | dark red-brown, 1.5-2.5 mm diam., glabrous. |
ashy brown, (1-)2-4(-5) mm diam., pubescent to tomentose. |
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 obovate to obtrullate, (50-)70-200 × (40-)70-200 mm, base rounded or cordate, blade not decurrent, margins with 3-5 shallow, often very broad lobes and 3-10 awns, apex acute to obtuse, rarely rounded; surfaces abaxially scurfy or with scattered pubescence, adaxially glossy, glabrous, secondary veins raised on both surfaces. |
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, 6-10 mm high × 13-18 mm wide, covering 1/3 nut, outer surface puberulent, inner surface pubescent, scale tips loose, especially at margin of cup, acute or acuminate; nut broadly ovoid or ellipsoid, 12-20 × 10-18 mm, often striate, glabrate, scar diam. 5-8 mm. |
Terminal | buds reddish brown, ovoid, 3-6.5 mm, puberulent throughout, occasionally densely pubescent on apical 2/3. |
buds conic or narrowly ovoid-ellipsoid, 5-10 mm, noticeably 5-angled in cross section, tawny pubescent. |
[r. | ||
c | . |
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Friesner | 1930. J. W. |
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Duffield | (1940) suggested that Friesner was counting bivalents; if so, then 2n = 24, consistent with all other reports for Quercus.] |
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2n | = 12. |
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Quercus nigra |
Quercus marilandica |
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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 | Poor shallow soils of glades, barrens and flatwoods, disturbed fields, rocky outcrops, and dry ridges |
Elevation | 0-450 m (0-1500 ft) | 0-900 m (0-3000 ft) |
Distribution |
AL; AR; DE; FL; GA; KY; LA; MD; MO; MS; NC; NJ; OK; SC; TN; TX; VA
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AL; AR; DC; DE; FL; GA; IA; IL; IN; KS; KY; LA; MD; MO; MS; NC; NE; NJ; NY; OH; OK; PA; SC; TN; TX; VA; WV
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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.) |
Evidence suggests that small trees from the western portion of the range (primarily Texas and Oklahoma) should be recognized as Quercus marilandica Münchhausen var. ashei Sudworth (D. M. Hunt 1989). These trees are characterized by 50-70 × 40-60 mm leaf blades with abaxial surfaces gray-tomentose in vein axils. Quercus marilandica reportedly hybridizes with Q. buckleyi and Q. falcata (E. J. Palmer 1948); and with Q. georgiana, Q. ilicifolia (= Q. ×brittoni W. T. Davis), Q. imbricaria [= Q. ×tridentata (A. de Candolle) Engelmann], Q. incana, Q. nigra, Q. phellos (Q. ×rudkini Britton), and Q. velutina (= Q. ×bushii Sargent). D. M. Hunt (1989) cited evidence of hybridization also with Q. arkansana, Q. hemisphaerica, Q. laevis, Q. laurifolia, Q. myrtifolia, Q. palustris, and Q. rubra. The Choctaw used Quercus marilandica to ease cramps and to aid in childbirth (D. E. Moerman 1986). (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 | |
Name authority | Linnaeus: Sp. Pl. 2: 995. (1753) | Münchhausen: Hausvater 5(1): 253. (1770) |
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