Once widespread across the American landscape, the fast-growing American chestnut tree has nearly disappeared in the last 100 years due to blight from imported Chinese chestnut trees. American chestnut trees are still cultivated and growing in forests. Today, most landscaping chestnut trees around the US are Chinese chestnut trees, favored for their broad shade branches, sweet nuts and disease resistance. Groups like the American Chestnut Foundation are working to reestablish the American chestnut tree by breeding American and Chinese varieties for blight-resistant trees.
Compare the leaves of the Chinese and American chestnut trees. The leaf of the American tree is longer and more deeply serrated. The leaves of the Chinese chestnut tree are more oval-shaped, with a lighter-color underside.
Feel the leaves of the two trees. American chestnut leaves are light and papery while the Chinese variety are thick and waxy.
Examine the stems of the two trees. American chestnut tree stems are smooth, hairless, and dark green or reddish brown. Chinese chestnut tree stems are tan or light green, and they're hairy. If there are buds on the trees, you will see that the buds on the American trees are pointy and grow at an angle while the buds on the Chinese trees grow close to the stems and are rounder.
Check the nuts of the American and Chinese chestnut trees. Both are covered with a green burr, but the spines on the American burrs are longer, thinner and denser than the burrs from Chinese trees.
Taste the chestnuts from the tree. Both types of nuts taste sweet, but American chestnuts are smaller than Chinese chestnuts. The shape of the American chestnuts is flatter, and the shells are covered in fine fuzz. Chinese chestnuts only have fuzz on the bottoms tips of the shells, and they are quite round.