The buckeye tree is a notable part of North American flora, recognized for its distinctive seed. This unique, shiny, dark brown seed often features a lighter patch, closely resembling a deer’s eye, which gives the tree its common name.
Identifying the Buckeye Tree
The term “buckeye” refers to several Aesculus species native to North America. The Ohio Buckeye (Aesculus glabra), Ohio’s state tree, is a prominent example. This deciduous tree typically grows 50 to 75 feet tall. It has palmately compound leaves, usually with five leaflets, which can emit an unpleasant odor when crushed. Its bark is often flaky or fissured with age, and it is among the first trees to develop leaves in spring.
Other North American species include the Red Buckeye (Aesculus pavia) and the Yellow Buckeye (Aesculus flava). Red Buckeyes are smaller, often growing as shrubs or small trees 15 to 25 feet tall. Their palmately compound leaves typically have five to seven leaflets, and the bark is smooth, becoming rougher with age. The Yellow Buckeye, known for its creamy yellow flowers, can reach 50 to 90 feet tall. It also features palmately compound leaves with five to seven leaflets, and its bark is often exfoliating or scaly.
Understanding the Buckeye Seed
The “buckeye” is the tree’s seed, enclosed in a leathery husk that splits open in the fall. These seeds are shiny and dark brown, featuring a prominent, lighter circular scar or “eye” where they were attached. This pale patch, known as the hilum, gives the seed its characteristic appearance.
Buckeye seeds, along with other parts of the plant such as leaves and bark, are toxic. They contain glycosides, including aesculin, saponins like aescin, and potentially alkaloids, which are harmful if ingested. Consuming buckeye seeds can lead to a range of adverse effects in humans and many animals, including severe gastrointestinal distress, vomiting, diarrhea, muscle weakness, and dilated pupils. In more serious cases, effects can include depression, paralysis, or stupor. Historically, some Native American tribes processed buckeye seeds to remove toxins through extensive leaching and roasting, making them edible, but this complex and dangerous process is not recommended for general practice.
Buckeye vs. Horse Chestnut
Buckeye trees and horse chestnut trees, both in the Aesculus genus, are often confused. Though related, they are distinct species with different origins. Buckeyes are native to North America, while the common horse chestnut (Aesculus hippocastanum) originated in Eurasia.
Key distinctions appear in their foliage and fruit. Horse chestnut trees typically have palmately compound leaves with seven leaflets, which are generally larger and stiffer than those of most buckeyes, while the Ohio Buckeye commonly has five. Horse chestnut fruit husks are notably prickly, whereas Ohio Buckeye husks are spiny or warty; Yellow Buckeye fruits, however, are smooth and lack spines. Additionally, horse chestnuts have large, sticky winter buds, a feature not typically found on buckeye species.