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. American hazelnut produces edible nuts that mature at a time between July and October. Each nut is enclosed in two leaf-like bracts with irregularly laciniate margins.The nuts are edible raw, although smaller than the more commonly cultivated filberts (Corylus maxima, Corylus colurna, Corylus avellana, and hybrids thereof).Native Americans used Corylus americana for medicinal purposes.