2. Quercus coccinea Muenchh. (scarlet oak)

Quercus coccinea var. tuberculata Sarg.

Pl. 415 e, f; Map 1840

Plants trees to 30 m tall. Bark medium to dark gray, divided into persistent ridges, the inner bark pinkish orange. Twigs 2–3 mm wide, usually dark brown, sometimes dark purplish brown or grayish, glabrous. Buds 5–7 mm long, brown, the lower scales glabrous except along the margins, the upper scales pubescent. Petioles 30–70 mm long. Leaf blades 11–20 cm long, 9.0–17.5 cm wide, truncate or very broadly obtuse at the base, divided 70–90% of the width, the lobes 3 or 4 per side, the largest lobes usually the middle pair (of 3) or third pair from the base (of 4); well-developed lobes 22–45(–60) mm wide, usually somewhat broadened outward, sometimes oblong, tapered or sometimes narrowly angled apically, with a few teeth and often 1 secondary lobe on each margin, each with 4–11 bristles 2–6 mm long (the whole blade with 25–54 marginal bristles), the strongest secondary veins reaching the margin at the tips of the lobes and ending in bristles, others reaching toward sinuses and turning aside before reaching the margin; the upper surface rather shiny, glabrous, the undersurface green, glabrous, smooth to the touch, the vein axils with small tufts of 5–10-rayed, stalked hairs. Acorn cups 12–17 mm long, 19–30 mm wide, covering 40–70% of the nut, bowl-shaped, the base prolonged, the inner surface smooth, glabrous or with a few hairs near the nut scar, the outer surface with the scales mostly distinctly convex-thickened at the base, pubescent. Nuts 15–17 mm long, 15–16 mm wide, ovoid to nearly cylindric, often with concentric grooves around the tip. 2n=24. April–May.

Scattered in the southeastern quarter of the state (eastern U.S. west to Wisconsin and Louisiana). Mesic to dry upland forests; often on acidic substrates.

Quercus coccinea is notable for the brilliant red color of its leaves in autumn. R. J. Jensen (1997) stated that the acorn cup encloses only 33–50% of the nut, but in many Missouri specimens the nut is more deeply (often much more deeply) enclosed. Plants in which the convex thickening of the acorn cup scale bases is particularly strong have been called var. tuberculata. In Missouri, only the hybrid between C. coccinea and C. velutina has been recorded; this may reflect the difficulty in distinguishing scarlet oak hybrids from other parents with deeply lobed leaves.