Ostrya virginiana

Ostrya virginiana (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.^[5][7] Very young twigs are sparsely fuzzy to thickly hairy; the hairs (trichomes) drop off by the next year.^[8]

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).^[5][7]

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,^[5] and arranged in groups of 1–4.^[7] The pistillate (female) catkins are 8–15 mm (5⁄16–19⁄32 in) long, containing 10–30 flowers each.^[5]

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.^[5] The involucre changes from greenish-white to dull brown as the fruit matures.^[7]

American hophornbeam is similar to its close relative American hornbeam (Carpinus caroliniana), which can be distinguished by its smooth bark and nutlets enclosed in open, three-lobed bracts.^[7]

•  
  Bark of a mature tree
•  
  Male catkins hanging from the branches in spring (United States Botanic Garden)
•  
  Leaf color in autumn
•  
  Two trees in winter with some dried leaves still hanging on their branches (marcescence)
•  
  An exceptionally large trunk

There are two subspecies:

• Ostrya virginiana subsp. guatemalensis (H.J.P.Winkl.) A.E.Murray – central and southern Mexico, Guatemala, Honduras, El Salvador^[9]
• 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.^[5]

In temperate areas of the US and Canada, Ostrya virginiana is found in lowland and foothill forests, where it is predominantly an understory tree.^[2]

In Mexico and Central America, Ostrya virginiana is found in cloud forests and humid portions of mid-elevation oak, pine–oak, and pine forests between 1200 and 2800 meters elevation.^[10]

The buds and catkins are important source of winter food for some birds, notably ruffed grouse (Bonasa umbellus).^[7] Additionally, the nutlets and buds are eaten by birds, deer, and rabbits.^[1]

It is not typically grown as an ornamental plant and is sometimes used as a street tree.^[11]

Its wood is very resilient and is valued for making tool handles and fence posts. ^[12]

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.^{[citation needed]}

• Metzger, F. T. (1990). "Ostrya virginiana". In Burns, Russell M.; Honkala, Barbara H. (eds.). Hardwoods. Silvics of North America. Vol. 2. Washington, D.C.: United States Forest Service (USFS), United States Department of Agriculture (USDA) – via Southern Research Station.

• Bioimages: Ostrya virginiana.
• University of Wisconsin – Green Bay. Trees of Wisconsin. Ostrya virginiana. Archived 2009-01-14 at the Wayback Machine
• 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.