Another common name of this tree is Ironwood. It is easy to identify Hop Hornbeam from its attractive and persistent hop-like fruits. In Illinois, its closest relative is another medium-small tree, Carpinus caroliniana (American Hornbeam). This latter tree has very smooth bark on its trunk, even when it is fully mature. The fruiting structure of American Hornbeam is quite different from the inflated sacs of Hop Hornbeam; the nutlets of American Hornbeam are subtended by 3-cleft bracts that are flat and open.

This native medium-small tree is up to 50' tall; it has a finely branched rounded crown. The trunk is up to 2' across. On mature trees, the bark of the trunk is rough-textured and greyish brown, dividing into narrow rectangular strips; this provides the trunk with a slightly shaggy appearance. The bark of smaller branches is more smooth and gray with small lenticels. The alternate leaves are 3-5" long and 1½–2½" across; they are ovate, pinnately veined, and doubly serrated along their margins. Each leaf tapers rather abruptly into a slender tip. The upper leaf surface is medium green and largely devoid of hairs, while the lower surface is pale green and slightly to moderately pubescent. The slender petioles are about ½" long, light green, and slightly to moderately pubescent. Because Hop Hornbeam is usually monoecious, the same tree has separate male and female flowers in the form of catkins. On rare occasions, some trees are unisexual. The male catkins are 1-2" long and narrowly cylindrical in shape; they are often arranged in groups of 3 and droop downward. The female catkins occur individually at the ends of branches; they are about ½" long and broadly cylindrical. The blooming period occurs during mid- to late spring. Cross-pollination of the flowers is achieved by wind. Afterwards, the inflorescence of female flowers begins to swell into a drooping compound fruit about 1½–2½" long and ¾–1" across; it has an appearance that is similar to the fruit of a hop vine. The nutlets of this fruit are enclosed within overlapping inflated sacs that are ovoid and somewhat flattened in shape. Initially, these sacs are greenish white and slightly shiny, but they later become dull brown. The woody root system produces no vegetative offsets; this tree reproduces by reseeding itself into new areas. Cultivation: Hop-Hornbeam adapts to many different situations, including those with full sunlight to light shade, moist to dry conditions, and soil containing loam, clay, or rocky material. This tree is slow to develop and its wood is strong and hard.

Ostrya guatemalensis (H.J.P. Winkl.) Rose:
Guatemala (Mesoamerica)

Ostrya italica var. guatemalensis H.J.P. Winkl.:
Costa Rica (Mesoamerica)
Guatemala (Mesoamerica)
Mexico (Mesoamerica)

Ostrya virginiana (Mill.) K. Koch:
Canada (North America)
El Salvador (Mesoamerica)
Guatemala (Mesoamerica)
Honduras (Mesoamerica)
Mexico (Mesoamerica)
United States (North America)

Mexico

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: Known only from Big Bend region of Texas (Brewster County) and adjacent northern Mexico.

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: Occurs from Nova Scotia to Manitoba and south to northeastern Wyoming, central Nebraska, Texas, and Florida.

This common tree can be found in all counties of Illinois (see Distribution Map). Typical habitats include mesic to dry deciduous woodlands, woodland edges, limestone glades, rocky wooded slopes, and abandoned fields. Hop Hornbeam is usually found in upland woodlands. It is sometimes cultivated as a lawn tree.

The shaggy bark and winter-exposed terminal staminate catkins of Ostrya virginiana permit easy recognition of this characteristic tree of dryish eastern forests. Along the Atlantic Coastal Plain, Ostrya virginiana , like Carpinus caroliniana , has smaller, blunter, often more pubescent leaves ( O . virginiana var. lasia Fernald). This variety has not been studied carefully; from the available material, however, it does not seem as distinct as the coastal subspecies in C . caroliniana . 

 Native Americans used Ostrya virginiana medicinally to treat toothache, to bathe sore muscles, for hemorrhages from lungs, for coughs, kidney trouble, female weakness, cancer of the rectum, consumption, and flux (D. E. Moerman 1986).

Trees , to 18 m; trunks short, crowns open, narrow to broadly rounded. Bark grayish brown or steel gray, shredding into narrow, sometimes rather ragged, vertical strips. Twigs sparsely pubescent to densely velutinous. Leaves: petiole glabrous to pubescent, without stipitate glands. Leaf blade narrowly ovate or elliptic to oblong-lanceolate, (5--)8--10(--13) × 4--5(--6) cm, base narrowly rounded to cordate or cuneate, margins sharply and unevenly doubly serrate, apex usually abruptly acuminate, sometimes acute or gradually tapering; surfaces abaxially sparsely to moderately pubescent (or sometimes densely villous), especially on major veins. Inflorescences: staminate catkins 2--5 cm; pistillate catkins 0.8--1.5 cm. Flowering with leaves in late spring. Infructescences 3.5--6.5 × 2--2.5 cm; bracts 1--1.8 × 0.8--1 cm. 2 n = 16.

Carpinus virginiana Miller, Gard. Dict. ed. 8, Carpinus no. 4. 1768; Ostrya virginiana subsp. lasia (Fernald) E. Murray; O. virginiana var. glandulosa Sargent; O. virginiana var. lasia Fernald

Comments: Igneous montane habitats in high mountains of Big Bend of Texas and adjacent Mexico.

Flowering late spring. Moist, open to forested hillsides to dry upland slopes and ridges, sometimes also on moist, well-drained flood plains; 0--300 m; Man., N.B., N.S., Ont., P.E.I., Que.; Ala., Ark., Conn., D.C., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., Nebr., N.H., N.J., N.Y., N.C., N.Dak., Ohio, Okla., Pa., R.I., S.C., S.Dak., Tenn., Tex., Vt., Va., W.Va., Wis., Wyo.

This common tree can be found in all counties of Illinois (see Distribution Map). Typical habitats include mesic to dry deciduous woodlands, woodland edges, limestone glades, rocky wooded slopes, and abandoned fields. Hop Hornbeam is usually found in upland woodlands. It is sometimes cultivated as a lawn tree.

The caterpillars of several moth species feed on the foliage of Hop Hornbeam (they are listed in the Moth Table); several of these moths are polyphagous. Other insects that feed on this tree include the leaf beetle Calligrapha ostryae, the long-horned beetle Hyperplatys maculata (its grubs bore through the wood or bark), the plant bugs Lygocoris ostryae and Reuteria fuscicornis, and the larvae of the sawfly Arge cyra. Several vertebrate animals rely on Hop Hornbeam as a source of food. These species include the Ruffed Grouse (buds, catkins), Downy Woodpecker (seeds), and Purple Finch (seeds). Among mammals, the Fox Squirrel, Red Squirrel, Woodland Deer Mouse, and White-Footed Mouse eat the seeds and buds, while the White-Tailed Deer browses on the twigs and leaves. Photographic Location: Crystal Lake Park in Urbana, Illinois, at the top of a wooded slope.

Note: For many non-migratory species, occurrences are roughly equivalent to populations.

Estimated Number of Occurrences: 6 - 20

Comments: Five EOs are known from Texas and 2 from Mexico.

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 8
Species: 11
Species With Barcodes: 1

Mexico

Rounded National Status Rank: N1 - Critically Imperiled

United States

Rounded National Status Rank: N1 - Critically Imperiled

Rounded Global Status Rank: T2 - Imperiled

Reasons: There are 7 known occurrences of Ostrya chisosensis: 5 in southern Texas, 2 in adjacent Mexico.

Canada

Rounded National Status Rank: N5 - Secure

United States

Rounded National Status Rank: N5 - Secure

Rounded Global Status Rank: G5 - Secure

Comments: Habitat relatively unsuited to other uses.

Biological Research Needs: None are strong needs at present.

Needs: None at present.

Comments: Name as a variety (var. chisosensis) in Ostrya virginiana apparently not yet formally published; cited as "comb. nov. ined." in Kartesz (1994, 1999); cf. Powell (1998). This combination has no entry in the International Plant Name Index as of October 2010, suggesting it has not yet been published.