|Distribution of American hazelnut|
Corylus americana, the American hazelnut or American hazel, is a species of deciduous shrub in the genus Corylus, native to the eastern and central United States and extreme southern parts of eastern and central Canada.
The American hazelnut grows to a height of roughly 2.5 to 5 m (8 to 16 ft), with a crown spread of 3 to 4.5 m (10 to 15 ft). It is a medium to large shrub, which under some conditions can take the like of a small tree. It is often multi-stemmed with long outward growing branches that form a dense spreading or spherical shape. It spreads by sending up suckers from underground rhizomes 10 to 15 cm (4 to 6 in) below the surface.
It blooms in very early to mid spring, producing hanging male (staminate) catkins 4 to 8 cm (1 1⁄2 to 3 1⁄4 in) long, and clusters of 2–5 tiny female (pistillate) flowers enclosed in the protective bracts of a bud, with their red styles sticking out at the tip. The male catkins develop in the fall and remain over the winter. Each one has a pair of bracts and four stamens.
Small bud-like female catkins and hanging male catkins
Corylus americana is cultivated as an ornamental plant for native plant gardens, and in wildlife gardens to attract and keep fauna in an area. There are cultivated hybrids of Corylus americana with Corylus avellana which aim to combine the larger nuts of the latter with the former's resistance to a North American fungus Cryptosporella anomala.
It is a medium to fast-growing species, that suckers moderately, eventually producing a multi-stemmed, clump appearance.
It adapts well to a range of soil pH and types, but does best on well-drained loams. American hazelnut prefers full sun for best growth and development. Though it can grow and persist in partial shade, plant density and fruit production are greatly reduced.
- Furlow, John J. (1997). "Corylus americana". 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.
- "Corylus americana". Germplasm Resources Information Network (GRIN). Agricultural Research Service (ARS), United States Department of Agriculture (USDA). Retrieved 2018-07-23.
- "Corylus americana". County-level distribution map from the North American Plant Atlas (NAPA). Biota of North America Program (BONAP). 2014.
- "Corylus americana". Missouri Botanical Garden. Retrieved 2016-07-05.
- Coladonato, Milo (1993). "Corylus americana". Fire Effects Information System (FEIS). US Department of Agriculture (USDA), Forest Service (USFS), Rocky Mountain Research Station, Fire Sciences Laboratory – via https://www.feis-crs.org/feis/.
- Hilty, John (2016). "American Hazelnut (Corylus americana)". Illinois Wildflowers.
- Chayka, Katy; Dziuk, Peter (2016). "Corylus americana (American Hazelnut)". Minnesota Wildflowers.
- Furlow, John J. (1997). "Corylus". 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.
- "Filbert", Hortus Third, 1976, p. 479, ISBN 0-02-505470-8
- Corylus americana Photos, drawings, description from Nature Manitoba.