Carpinus caroliniana (American hornbeam) is a small hardwood tree in the genus Carpinus. American hornbeam is also known as blue-beech, ironwood, and musclewood. It is native to eastern North America, from Minnesota and southern Ontario east to Maine, and south to eastern Texas and northern Florida. It also grows in Canada (southwest Quebec and southeast Ontario). It is a small tree reaching heights of 10–15 m, rarely 20 m, and often has a fluted and crooked trunk. The bark is smooth and greenish-grey, becoming shallowly fissured in all old trees. The leaves are alternate, 3–12 cm long, with prominent veins giving a distinctive corrugated texture, and a serrated margin. The male and female catkins appear in spring at the same time as the leaves. The fruit is a small 7–8 mm long nut, partially surrounded by a three- to seven-pointed leafy involucre 2–3 cm long; it matures in autumn. The seeds often do not germinate till the spring of the second year after maturating.