Though it was once among the most common trees in forests in the eastern United States, the American chestnut was almost completely wiped out by a fungal blight in the first half of the 20th century. A few American chestnut trees have survived, and horticulturalists are working to breed trees that are immune to the blight. The American chestnut is a tall tree, reaching up to 100 feet high in the wild and producing rich-tasting nuts.
Look at the leaves of the tree. A chestnut is a deciduous broadleaf, so its leaves are flat and thin, and the tree sheds all its leaves each fall.
Next, look at how the leaves attach to the tree. The leaves of the chestnut tree are simple, which means that each individual leaf attaches directly to the branches of the tree. By contrast, a tree with compound leaves has groups of leaves attached to a stem, which in turn attaches to the tree.
Now look to see if the leaves are exactly opposite one another, or if they have spaces between the stem of one leaf and the next. The leaves of the chestnut tree follow the latter pattern, which is called alternate leaves.
Look at the size and shape of the leaves. Chestnut trees have dark green leaves that are between 3 and 5 inches long. They are oval, glossy on top and smooth on their backsides, with tooth-shaped indentations along their edges. They are not fan-shaped or lobed like mittens.
Look for nuts and the husks they grow in on the ground around the tree. The nuts of the chestnuts grow in rough burrs that split when the nut ripens, revealing the nuts inside. The nuts are rounded on top, pointed on the bottom and dark brown.
Now, look at the tips of the tree's twigs. Chestnut trees have one small bud (no more than a quarter-inch long) at the end of each twig.