1. Ostrya virginiana (Mill.) K. Koch (eastern hop hornbeam, ironwood)

O. virginiana var. lasia Fernald

Pl. 303 j, k; Map 1279

Plants small trees (3.5–)5.0–10.0 m tall, the bark scaly, light reddish gray to grayish brown. Young growth not sticky or resinous. Twigs grayish brown, about 1 mm thick, pubescent with long, soft, loosely appressed hairs. Buds sessile, with mostly 5–7 scales. Petioles 2–9 mm long. Leaf blades 6–13 cm long, 3.0–7.5 cm wide, narrowly elliptic or narrowly obovate, the undersurface green, pubescent with spreading hairs, felty and soft to the touch, the tip tapered to a sharp point, the base shallowly cordate to rounded, the margins sharply toothed to the base, without lobes, the lateral veins 10–16 on each side of the midrib, sometimes branched. Stamens 3, each divided almost to the base. Fruits nutlets, 5–6 mm long, ovate in outline, strongly flattened, the shell thin, smooth, whitish green, arranged in dense, elongate spikes 3–6 cm long with mostly 10–25 nutlets. Bracts 12–25 mm long, papery, inflated, lightly but distinctly veined, tan or pale green, hairy, completely enclosing the nutlets and falling with them. 2n=16. April–May.

Scattered nearly throughout the state (eastern U.S. west to North Dakota, Wyoming, and Texas; Canada). Borders of mesic to dry upland forests, glades, savannas, ledges and tops of bluffs, and rarely margins of fens and banks of streams.

The wood of the hop hornbeam is extremely hard and strong, and it was once widely used for small items such as tool handles. The usefulness of hop hornbeam for lumber is limited by the small size of the trees, and it has been used almost exclusively by local craftsmen and artisans. It is seldom seen in the nursery trade, perhaps because it grows fairly slowly, although it has performed well when tried.

Pubescence of the twigs is variable. Plants with unusually dense hairs have been called var. lasia, but these appear to grade into those with more typical pubescence. Individuals with stout, long-stalked glands on the twigs, petioles, and midribs have been called f. glandulosa (Spach) J.F. Macbr. The glandular form is common across the northern edge of the species’ range, but it is rare in Missouri.