|A hophornbeam branch with the characteristic hops, in early summer|
|Generalized native range|
Ostrya virginiana, the American hophornbeam, is a species of Ostrya native to eastern North America, from Nova Scotia west to southern Manitoba and eastern Wyoming, southeast to northern Florida and southwest to eastern Texas. Populations from Mexico and Central America are also regarded as the same species, although some authors prefer to separate them as a distinct species, Ostrya guatemalensis. Other names include eastern hophornbeam, hardhack (in New England), ironwood, and leverwood. 
American hophornbeam is a small deciduous understory tree growing to 18 m (59 ft) tall and 20–50 centimetres (8–20 in) trunk diameter. The bark is brown to gray-brown, with narrow shaggy plates flaking off, while younger twigs and branches are smoother and gray, with small lenticels. Very young twigs are sparsely fuzzy to thickly hairy; the hairs (trichomes) drop off by the next year.
The leaves are ovoid-acute, 5–13 cm (2–5 in) long and 4–6 cm (1 1⁄2–2 1⁄4 in) broad, pinnately veined, with a doubly serrated margin. The upper surface is mostly hairless, while the lower surface is sparsely to moderately fuzzy (rarely densely hairy).
The flowers are catkins (spikes) produced in early spring at the same time as the new leaves appear. The staminate (male) catkins are 2–5 cm (3⁄4–2 in) long, and arranged in groups of 1–4. The pistillate (female) catkins are 8–15 mm (5⁄16–19⁄32 in) long, containing 10–30 flowers each.
Pollinated female flowers develop into small nutlets 3–5 mm (1⁄8–3⁄16 in) long fully enclosed in a papery sac-shaped involucre 10–18 mm (3⁄8–11⁄16 in) long and 8–10 mm (5⁄16–3⁄8 in) wide. The involucre changes from greenish-white to dull brown as the fruit matures.
Male catkins hanging from the branches in spring (United States Botanic Garden)
Two trees in winter with some dried leaves still hanging on their branches (marcescence)
There are two subspecies:
- Ostrya virginiana subsp. guatemalensis (H.J.P.Winkl.) A.E.Murray – central and southern Mexico, Guatemala, Honduras, El Salvador
- Ostrya virginiana subsp. virginiana – eastern half of United States, eastern Canada
Populations along the Atlantic coast have slightly smaller leaves, and are sometimes separated as O. virginiana var. lasia Fernald.
It is grown as an ornamental plant and is sometimes used as a street tree.
Its wood is very resilient and is valued for making tool handles and fence posts.
Being a diffuse porous hardwood and having extremely high density and resistance to compression, it is an excellent material for the construction of wooden longbows.
- "Ostrya virginiana". Natureserve.org. 2015. Retrieved 16 September 2017.
- "Ostrya virginiana". World Checklist of Selected Plant Families (WCSP). Royal Botanic Gardens, Kew.
- "Ostrya virginiana". County-level distribution map from the North American Plant Atlas (NAPA). Biota of North America Program (BONAP). 2014.
- Furlow, John J. (1997). "Ostrya virginiana". In Flora of North America Editorial Committee. Flora of North America North of Mexico (FNA). 3. New York and Oxford – via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
- Nelson Sutherland, C.H. (2008). Catálogo de las plantes vasculares de Honduras. Espermatofitas: 1-1576. SERNA/Guaymuras, Tegucigalpa, Honduras
- Hilty, John (2016). "Hop Hornbeam (Ostrya virginiana)". Illinois Wildflowers.
- Chayka, Katy; Dziuk, Peter (2016). "Ostrya virginiana (Ironwood)". Minnesota Wildflowers.
- Whittemore, Alan. "Ostrya virginiana". Flora Mesoamericana. Missouri Botanical Garden – via Tropicos.org.
- Metzger, F. T. (1990). "Ostrya virginiana". In Burns, Russell M.; Honkala, Barbara H. Hardwoods. Silvics of North America. Washington, D.C.: United States Forest Service (USFS), United States Department of Agriculture (USDA). 2 – via Southern Research Station (www.srs.fs.fed.us).
|Wikimedia Commons has media related to Ostrya virginiana.|
- Bioimages: Ostrya virginiana.
- University of Wisconsin – Green Bay. Trees of Wisconsin. Ostrya virginiana.
- Virginia Tech Dendrology. Ostrya virginiana Fact Sheet.
- University of Connecticut. Plants Database. Ostrya virginiana.
- Trees, Shrubs, and Woody Vines of North Carolina. Hophornbeam (Ostrya virginiana).
- Yale University. Cyber Flora. Ostrya virginiana.