1. Quercus acutissima Carruth. (sawtooth oak)

Pl. 414 l, m; Map 1839

Plants trees to 30 m tall. Bark medium to dark gray, divided into narrow, persistent ridges. Twigs 2–3 mm thick, dark brown, minutely pubescent with 1–5-rayed, appressed (occasionally spreading) hairs, sometimes nearly glabrous. Buds 6–8 mm long, pubescent (at least on the apical half), brown, the scales glabrous on the surface, hairy along the margins. Leaves with the petiole 15–40 mm long. Leaf blades 14–21 cm long, 3.5–6.0 cm wide, oblong-lanceolate to lanceolate, rounded to truncate at the base, tapered to a sharply pointed tip, the margins sharply toothed, but not lobed, the teeth 10–18 per side, broadly angled to tapered, each ending in 1 bristle 2–5 mm long, the secondary veins (except the basalmost) reaching the margin at the tip of a tooth and extended into the bristle; the upper surface shiny, with scattered, inconspicuous, simple (rarely 2–4-rayed) hairs, the undersurface green, with inconspicuous, unbranched, appressed hairs between the veins, the veins with unbranched spreading hairs, the vein axils with small tufts of more or less 4-rayed stalked hairs. Styles linear or narrowly spatulate, the tip not or only weakly broadened. Pistillate flowers with the sepals fused to the ovary. Fruits ripening the second autumn after flowering, sessile or the stalk to 2 mm long. Acorn cups 14–15 mm long, 18–25 mm wide, hemispheric, covering 30–50% of the nut, the inner surface smooth, hairy, the outer surface with the scales 8–10 mm long, narrowly lanceolate or strap-shaped from a short, triangular, weakly convex base, the tips spreading to strongly recurved, those at the margin extending past the rim of the cup, longer than the other scales but not noticeably differentiated. Nuts 15–20 mm long, 13–17 mm wide, ovoid to ovoid-cylindrical, smooth or occasionally with weak concentric grooves around the tip, the inner surface of the shell free from the seedcoat (except basally), densely pubescent, with abortive ovules near the base. 2n=24. April.

Introduced, uncommon and widely scattered (native of Asia; introduced sporadically in the eastern U.S.). Mesic upland forests; also parks, roadsides, and disturbed areas.

Quercus acutissima is becoming more common in horticulture. It was first reported to escape in Missouri by Yatskievych and Summers (1993). In addition to its use as an ornamental, the species also sometimes is grown in plantations to attract wildlife (especially turkeys), because some cultivars are relatively fast-growing and produce copious quantities of acorns at a relatively early age. Whittemore (2004) discussed the establishment of this potentially invasive exotic taxon since it was first recognized as spreading from cultivated plants in the early 1990s.