Northern Red Oak/Quercus rubra

Shumard Oak
Quercus shumardii Buckl.

Bark dark gray to blackish, relatively smooth at first, then breaking into scaly ridges. Branches spreading to ascending. Twigs about 5 mm in diameter, olive green then turning dark reddish. Buds clustered at apex 5 to 7 mm long, sharp pointed, strongly angled. Leaves alternate, deciduous, simple; oval to slightly obovate, 10 to 20 cm long, 6 to 15 cm wide; with 7 to 10 bristle-tipped lobes, lobes on upper crown leaves narrower to slightly wider than sinuses, lobes on lower crown leaves wider than sinuses; dark green above, paler below, glabrous except for vein axils on lower surface; petiole about 5 cm long. Flowers unisexual; staminate in yellow catkins appearing with the unfolding leaves; pistillate on pubescent peduncles. Fruit an acorn; cup 20 to 31 mm across, enclosing about one-fourth of the nut; nut about 25 mm long, 15 mm in diameter.

Shumard Oak/Quercus shumardii

Blackjack Oak
Quercus marilandica Muenchh.

Bark black, very rough, consisting of thick blocky plates. Branches stout, spreading to drooping. Twigs stout, about 5 mm in diameter. Buds with rusty brown hairs, about 4 to 8 mm long. Leaves alternate, tardily deciduous, simple, 7 to 25 cm long, broadly obovate at apex (bear-paw shape) tapering to a narrow base, margin entire or with 3 bristle-tipped apical lobes, upper surface dark green, rusty pubescent on undersurfaces. Flowers unisexual; staminate in catkins, appearing with the leaves; pistillate solitary or paired. Fruit an acorn, cup enclosing one-half to two-thirds of the nut; nut nearly ovoid, 20 to 25 mm long by 15 to 20 mm in diameter.