Nuts That Grow on Trees Covered in Thorns

American Chestnut

• The American chestnut (Castanea dentata) was once abundant in old-growth forests across the Eastern United States. An outbreak of chestnut blight (Cryphonectria parasitica) in the 1950s nearly wiped the species out completely, but they are making a comeback. American chestnuts can be identified by their simple elongated alternative leaves measuring 5 to 8 inches long. The leaves have a leathery texture. Nuts are encased in a skin covered in spines, much like large burs. Nuts appear in groups of two or three, their spiny skins splitting when the nuts are ripe.

Chinese Chestnut

• Chinese chestnuts (Castanea mollissima) resemble American chestnuts, but are generally smaller and have no problems with chestnut blight. Flowers are often used to identify the Chinese chestnut since they emit a pungent and particularly foul odor. Both Chinese and American chestnuts bear edible fruits, therefore the somewhat difficult task of distinguishing immature trees is not vital.

Horse Chestnut

• Horse chestnuts (Aesculus hippocastanum) are not chestnuts at all, but members of the buckeye family. They are often found in the wild, growing up to 100 feet tall. Their leaves are compound, each group arranged in a nearly circular mass. Horse chestnuts produce impressive, showy white flowers in spring, followed by nuts covered in a thick skin studded with spines. The nuts are poisonous and should not be ingested -- they are easily distinguished from chestnuts, which have a fuzzy appearance.

Ohio Buckeye

• Ohio buckeyes (Aesculus glabra) resemble their cousins, the horse chestnuts. They share leaf shape and growth habit, but the Ohio buckeye tends to be smaller, only growing to about 70 feet. Fruits are similarly shaped, but instead of being studded with extremely sharp points, Ohio buckeye spikes are far less pronounced, often appearing as tall bumps. All parts of this tree are poisonous, do not consume or crush any plant tissues.