Carpinus Caroliniana

Carpinus caroliniana (American hornbeam) is a small hardwood tree in the genus Carpinus. American hornbeam is also occasionally known as blue-beech, ironwood, or 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), Mexico (central and southern), Guatemala, and western Honduras.

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 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.

There are two subspecies, which intergrade extensively where they meet:

• Carpinus caroliniana subsp. caroliniana. Atlantic coastal plain north to Delaware, and lower Mississippi Valley west to eastern Texas. Leaves mostly smaller, 3–9 cm long, and relatively broader, 3–6 cm broad.
• Carpinus caroliniana subsp. virginiana. Appalachian Mountains and west to Minnesota and south to Arkansas. Leaves mostly larger, 8–12 cm long, and relatively narrower, 3.5–6 cm broad.

It is a shade-loving tree, which prefers moderate soil fertility and moisture. It has a shallow, wide-spreading root system. The wood is heavy and hard, and is used for tool handles, longbows, walking sticks, walking canes and golf clubs. The leaves are eaten by the caterpillars of some Lepidoptera, for example the Io moth (Automeris io).