Quercus nigra |
Quercus agrifolia |
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chêne gris, water oak |
California live oak, coast live oak, encina |
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Habit | Trees, deciduous or tardily deciduous, to 30 m. Bark grayish black, fissures irregular, shallow, inner bark pinkish. | Trees, evergreen, to 25 m. Bark gray to dark brown or black, ridges broad, rounded. |
Twigs | dark red-brown, 1.5-2.5 mm diam., glabrous. |
brown to red-brown, 1.5-3 mm diam., with scattered pubescence or uniformly pubescent. |
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 broadly elliptic to ovate or oblong, 15-75 × 10-40 mm, base rounded or cordate, margins entire or spinose, with up to 24 awns, apex blunt to attenuate; surfaces abaxially glabrous or with small axillary tufts of tomentum, veins raised, adaxially distinctly convex, rugose, glabrous, occasionally densely uniformly pubescent. |
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. |
annual; cup turbinate to cup- or bowl-shaped, rarely saucer-shaped, 9-13 mm high × 9-15 mm wide, covering 1/4-1/3(-1/2) nut, outer surface glabrous to sparsely puberulent, inner surface pubescent on innermost 1/3 to uniformly pubescent, scales acute, tips loose; nut ovoid to oblong or conic, 15-35 × 10-15 mm, glabrous, scar diam. 3.5-8 mm. |
Terminal | buds reddish brown, ovoid, 3-6.5 mm, puberulent throughout, occasionally densely pubescent on apical 2/3. |
buds light chestnut brown, ovoid, occasionally subconic, 3-6(-7) mm, glabrous except for cilia along scale margins. |
2n | = 24. |
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Quercus nigra |
Quercus agrifolia |
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Phenology | Flowering spring. | Flowering early to mid spring. |
Habitat | Mesic alluvial and lowland sites, also barrens, dunes, hammocks, and low ridges to steep slopes | Moderately dry sites |
Elevation | 0-450 m (0-1500 ft) | 0–1400 m (0–4600 ft) |
Distribution |
AL; AR; DE; FL; GA; KY; LA; MD; MO; MS; NC; NJ; OK; SC; TN; TX; VA
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CA; Mexico (Baja California)
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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.) |
Quercus agrifolia is found in the Coast Ranges from Sonoma County, California, south to Baja California. Plants with densely pubescent leaves, especially abaxially, have been treated as Q. agrifolia var. oxyadenia. This species reportedly hybridizes with Quercus kelloggii and Q. wislizenii. The Mahuna used Quercus agrifolia medicinally to heal the bleeding navel of a newborn (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 | Q. acroglandis, Q. agrifolia var. oxyadenia, Q. pricei |
Name authority | Linnaeus: Sp. Pl. 2: 995. (1753) | Nee.: Anales Ci. Nat. 3: 271. (1801) |
Web links |