The buckeye, a common sight in many landscapes, often sparks confusion due to its appearance. While it might look appealing, the buckeye is not a true nut and is, in fact, toxic. This distinction is important for public understanding and safety.
Understanding Buckeye Botany
A buckeye is botanically classified as a seed, not a true nut. It belongs to the genus Aesculus, commonly known as horse chestnuts, which is part of the soapberry family (Sapindaceae). A true nut is a simple, dry fruit with one seed, where the ovary wall becomes hard and woody at maturity and does not open to release the seed. Examples of true nuts include chestnuts, hazelnuts, and acorns.
Buckeyes, conversely, develop inside a leathery capsule that contains one to three glossy brown seeds. These capsules are often spiny or warty and split open to release the seeds. The presence of a pale scar, resembling a deer’s eye, on the seed is a characteristic feature that gives the buckeye its name. The Aesculus genus includes several species, such as Ohio buckeye (A. glabra) and California buckeye (A. californica), which are native to North America.
The Toxicity of Buckeyes
Buckeyes are poisonous. All parts of the buckeye tree, including the leaves, bark, flowers, and especially the seeds, contain toxic compounds. The primary toxic compounds found in buckeyes are glycosides like aesculin, saponins, and possibly narcotic alkaloids. These substances can cause a range of adverse effects if ingested.
Symptoms of buckeye poisoning include gastrointestinal upset, such as nausea, vomiting, and diarrhea. More severe symptoms may involve muscle weakness, trembling, incoordination, dilated pupils, paralysis, or convulsions. While severe poisoning is less common, ingestion of even a small amount can cause discomfort. Seeking immediate medical attention is important if buckeyes are ingested.
Buckeyes Versus True Nuts
Differentiating buckeyes from edible chestnuts is important to prevent accidental ingestion, as they are often confused. Buckeyes (Aesculus species) are not related to true chestnuts (Castanea species), which belong to a different family (Fagaceae). True chestnuts have a very spiny bur that contains multiple nuts. These nuts often have a pointed end or a small tuft.
In contrast, buckeye seeds are found within a smoother or mildly spiny capsule that contains only one large, glossy brown seed. The buckeye seed is distinctly rounder and features a prominent pale scar. The leaves also differ; true chestnuts have simple, serrated leaves, while buckeyes have palmately compound leaves with five to seven leaflets radiating from a central point.