To identify different types of chestnuts, examine the husk or pod the nut comes in as well as the color and tassel of the seed itself. The leaves of the chestnut tree and presence of burs and acorns also help to identify types of chestnuts.
Identify chestnuts by examining the husks of the nuts and determining the types of spikes or spines the husk has. Edible sweet chestnuts have large, spiky husks that look like porcupines. The horse chestnut is toxic and is distinguished from edible chestnuts because horse chestnuts come in pods that resemble round balls with short, bumpy spikes.
Another way to identify chestnuts is to look at the chestnut seed inside the pod. Edible chestnut seeds are brown and have a tassel at the top. The tassel sticks up like a point and feels stiff and slightly sharp. Horse chestnut seeds are also brown in color but lack the tassel that edible chestnuts have.
Look at the color, teeth, hairs and veins of leaves to identify chestnuts. The American chestnut has veined leaves with large teeth and no hairs on them while the Chinese chestnut has veined leaves with small teeth and hairy leaf undersides. The toxic horse chestnut's leaves have fine teeth and come in leaflets of five.