Quercus phellos

Linnaeus

Sp. Pl. 2: 994. 1753.

Common names: Willow oak
EndemicIllustrated
Treatment appears in FNA Volume 3.

Trees, deciduous, to 30 m. Bark dark gray and smooth, becoming darker and irregularly fissured with age, inner bark light orange. Twigs reddish-brown, 1-2 mm diam., glabrous. Terminal buds chestnut-brown, ovoid, 2-4 mm, apex acute, glabrous. Leaves: petiole 2-4 (-6) mm, glabrous, rarely sparsely hairy. Leaf-blade linear to narrowly elliptic, usually widest near middle, 50-120 × 10-25 mm, base acute, margins entire with 1 apical awn, apex acute; surfaces abaxially pale green, glabrous, rarely softly pubescent, adaxially light green, glabrous. Acorns biennial; cup shallowly saucer-shaped, 3-6.5 mm high × 7.5-11 mm wide, covering 1/4-1/3 nut, outer surface puberulent, inner surface light-brown, pubescent, scale tips tightly appressed, acute; nut ovoid to hemispheric, 8-12 × 6.5-10 mm, often striate, glabrate, scar diam. 4.5-6 mm.


Phenology: Flowering spring.
Habitat: Of bottomland flood plains, also on stream banks, dunes, and terraces, and, occasionally, on poorly drained uplands
Elevation: 0-400 m

Distribution

V3 947-distribution-map.gif

Ala., Ark., Del., D.C., Fla., Ga., Ill., Ky., La., Md., Miss., Mo., N.J., N.Y., N.C., Okla., Pa., S.C., Tenn., Tex., Va.

Discussion

Individual trees with leaves softly pubescent abaxially may be classified as Quercus phellos forma intonsa Fernald; however, such leaves are known to occur on second-flush shoots from twigs bearing typical leaves.

Quercus phellos reportedly hybridizes with Q. coccinea (W. W. Ashe 1894); with Q. ilicifolia (= Q. ×giffordi Trelease) and Q. incana (E. J. Palmer 1948); and with Q. marilandica, Q. nigra, Q. pagoda (= Q. ×ludoviciana Sargent), Q. palustris, Q. rubra, Q. shumardii, and Q. velutina. D. M. Hunt (1989) cited evidence of hybridization also with Q. hemisphaerica, Q. imbricaria, Q. laurifolia, and Q. pumila.

Selected References

None.

Lower Taxa

None.
... more about "Quercus phellos"
Kevin C. Nixon +
Linnaeus +
furrowed +  and smooth +
darker;dark gray +
fissured +
2-6-lobed +
pistillate +, capitate +  and spicate +
Willow oak +
connate +  and distinct +
starchy +  and fleshy +
tuberculate +
saucer--shaped +
×7.5-11 +, 3mm +  and 6.5mm +
multibracteate +, spiny +  and scaly +
Ala. +, Ark. +, Del. +, D.C. +, Fla. +, Ga. +, Ill. +, Ky. +, La. +, Md. +, Miss. +, Mo. +, N.J. +, N.Y. +, N.C. +, Okla. +, Pa. +, S.C. +, Tenn. +, Tex. +  and Va. +
0-400 m +
pistillate +  and staminate +
biennial +, annual +  and maturation +
1-seeded +  and winged +
in groups +  and enclosed +
Of bottomland flood plains, also on stream banks, dunes, and terraces, and, occasionally, on poorly drained uplands +
pistillate +, spicate +  and staminate +
silky-tomentose +
5 cm50 mm <br />0.05 m <br /> (12 cm120 mm <br />0.12 m <br />) +
unlobed +  and lobed +
arranged +  and alternate +
toothed +  and entire +
10mm;25mm +
0.8 cm8 mm <br />0.008 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
1/4 +  and 1/3 +
ovoid +  and hemispheric +
0.65 cm6.5 mm <br />0.0065 m <br /> (1 cm10 mm <br />0.01 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
hairy +  and glabrous +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
Flowering spring. +
distinct +
few-to-many +
reduced +
0.45 cm4.5 mm <br />0.0045 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
anastomosing +, branching +  and unbranched +
W1 +, Endemic +  and Illustrated +
inconspicuous +
distinct +
linear-spatulate +
light green +  and pale green +
glabrous +  and pubescent +
Quercus phellos +
Quercus sect. Lobatae +
species +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
bristle-tipped +
reddish-brown +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +