Eastern hophornbeam (Ostrya virginiana): what the agencies record

This page reports what US federal publications say about one tree. It does not identify trees from descriptions or photos and does not say what should be done with any tree. The family overview, tree species in the agency records, explains the sources and holds the comparison table. A close relative is covered at American hornbeam.

At a glance

Item	What the source records
Scientific name	Ostrya virginiana (Mill.) K. Koch, birch family (Silvics and PLANTS)
Other names, Silvics	American hophornbeam, hornbeam, leverwood and "ironwood"; the Wood Handbook files it under ironwood in its table of species names
Native status, USDA PLANTS	Native in Canada and the lower 48 states
Size, Silvics	Normally under 30 cm (12 in) in diameter and under 12 m (40 ft) tall, except in east Texas and south Arkansas where 15 to 18 m (50 to 60 ft) is reached; the largest tree, found in Michigan in 1976, is 91 cm (36 in) in diameter, 22 m (73 ft) tall, with a crown spread of 27 m (88 ft)
Green weight of the wood, NRS-38	60 lb per cubic foot, without bark

Native range, climate and soils

The Silvics of North America handbook (Agriculture Handbook 654, Volume 2, 1990) calls eastern hophornbeam a small, short-lived tree scattered in the understory of hardwood forests, with a slow to medium growth rate on a great variety of soils. It occurs through most of the eastern half of the United States, from Cape Breton and Prince Edward Island west through southern Ontario and northern Michigan to southeastern Manitoba, and south into North Dakota, the Black Hills of South Dakota and northeastern Wyoming. It is also found in the mountains of Mexico south to El Salvador and Honduras. The handbook gives the northwestern corner of the range as 460 mm (18 in) of precipitation a year with a frost-free season of 100 days, and the Gulf coast as 1,630 mm (64 in) with 290 days.

Silvics says the species grows on soils of all the major orders in the eastern United States, and that its site range widens northward. At the northern edge it is found on dry-mesic to xeric sites, shallow soils and bedrock outcrops on upper slopes and ridgetops. In the Appalachians mesic sites are most favorable, and in the Smokies and the southern Cumberland Plateau it is limited to north slopes, protected lower slopes, ravines and coves.

Flowers and fruit

The species is monoecious. The handbook says one to three male catkins develop at the ends of branches late in the summer before the female flowers, with pollen formed in spring and carried by wind, and solitary female catkins appearing as the leaves start to develop. Flowering is between March 25 and April 16 in the Southeast and between mid-May and mid-June in the North. The fruits are ripe by the end of August in Michigan and as late as October in the South; the nuts are 7 mm (0.3 in) long inside an inflated sac 20 mm (0.8 in) long that helps wind dispersal, and the hoplike strobile begins to break up right after ripening. Trees begin to be fruitful at age 25. Seeds need stratification to overcome internal dormancy; Silvics gives potential germination of 85 to 90 percent and germination capacity of only 27 to 65 percent.

Size, shade and growth

The handbook says the tree is shade tolerant, grows in climax forests in the northern part of its range and reproduces well under full shade. In the South it is associated with later seral stages that follow pioneer pine communities, first appearing in Piedmont pine stands after they reach what it calls "about 90 years old." Slow growth and small size earn it the title "weed" throughout its range, the handbook says, and in some southern areas it is considered the number one weed species; managed timber stands usually discriminate against it. In Michigan stands subcanopy trees average 9.9 m (32.5 ft) tall after 50 years, with the peak growth of 3.3 m (10.8 ft) in the first decade. Diameter growth under individual tree selection in Wisconsin and Michigan averages 12 to 13 mm (0.48 to 0.51 in) per decade.

Wood

Silvics says the wood is extremely hard, and that the tree is not large enough for commercially important lumber but is used locally. The Wood Handbook (FPL-GTR-282, 2021) has no strength row for eastern hophornbeam in Table 5-3b; it lists the species only in its table of standard names. The NRS-38 weight table does list it:

NRS-38 figure (Table 1A)	Value
Specific gravity, 12% moisture content volume basis	0.70
Specific gravity, green volume basis	0.63
Moisture content as a percent of oven-dry weight	53
Green weight, lb per cubic foot, without bark	60

The green weight is the figure used in the log weight calculator.

Damaging agents the handbook names

Silvics calls trunk and butt rots the most important disease problems and says the species is one of the most defective in Ontario, where defect claims 20 percent of the gross merchantable cubic foot volume of trees over 10 cm (4 in) in diameter. Losses are greatest in trees 95 to 140 years old and over 18 cm (7 in) in diameter, with cull averaging 32 percent, brown stains causing 62 percent of the defect, and the organisms primarily responsible named as Stereum murrayi, Phellinus igniarius and Pholiota limonella. The handbook otherwise calls the species relatively free of insect and other disease problems. It is not readily injured by cold, with succulent growth undamaged until temperatures fell below minus 8 degrees C (17 degrees F) in Wisconsin, and its tough, resilient branches resist wind, snow and ice damage. It is sensitive to pollutants in the upper Ohio River Valley, where it does not grow in areas with high exposure to oxides of sulfur or nitrogen, or to chlorine or fluorine.

The handbook says white-tailed deer browse it only incidentally, beaver in Ohio prefer it, and its buds and catkins are an important winter food for ruffed grouse. For who takes reports of regulated pests, see reporting a pest in the United States, and pests and diseases by country sets out which ones agencies regulate.