Compare sources for Quercus phellos

southeastern U.S.A.; 0-400 m; introduced in Europe in 1723;

15-30 m tall; crown dense, rounded; trunk short, to 1.6 m in diameter;

Deciduous, large tree often to 80’

5-13 x 1-2.5 cm; lanceolate; limp; margin entire, untoothed, sometimes wavy; apex pointed and mucronate; base cuneate; pale green above; sometimes pubescent beneath; young leaves yellow; midrib raised; petiole hairless, 2-5 mm long;

• 4”
• very narrow w/ short petiole
• underleaf sometimes fuzzy
• fall color yellow to pale orange-brown
• narrow leaves tand out stiffly all around the twig

acorn 1 cm in diameter, ovoid or subglobose; singly or paired; apex pointed; yellow brown, sometimes striate; cup shallow, covering 1/4 to 1/2 of nut, thin, greenish brown; maturing in 2 years;

• 1/2”
• cup shallow
• covers 1/4 - 1/3 nut
• tight grayish scales

smooth with faint ridges

very slender for an oak

smaller than similar species

hardy; prefers wet soils; fast growing;

• Common in bottomlands and other wet lowland, occassionaly on poorly drained uplands
• Common in cultivation in yards and towns
• Zones 7-9s

Field Notes:
I am forming a theory that these can be reliable separated by the following:

• Twig color - phellos - gray; nigra brown – this can be tough
• Midrid and twig end color - nigra can sometimes (often?) be red, phellos not
• Leaves - while nigra can have totally linear leaves with an acute tip, there will always? be at least some sign on one of the leaves of lobing, even if only a swelling. This only works if there are enough leaves seen in the photo(s).

The distal lobing is indicative of Q nigra. Q phellos can have lobing but in my experience and research I believe it will never be distal, only proximal from the midpoint. Another point for Q nigra is that Q phellos does not have the severely constricted proximal portion of the leaf as seen on some of these leaves, towards the upper left in the photo.

– A. Camus : 410 – Sub-genus Quercus, section Lobatae, subsection Phellos; – Numerous hybrids, among them : x giffordi Trel. with Q.ilicifolia , x ludoviciana Sarg. with Q.pagoda ;