Many people encounter the unusual, bumpy green fruit known as a “horse apple” and wonder about its safety. These distinctive growths, scientifically called Maclura pomifera, often spark curiosity, particularly regarding whether they pose a risk to humans or animals.
What Exactly Are Horse Apples?
Horse apples are the large, spherical, bumpy fruits of the Osage orange tree (Maclura pomifera), also commonly known as hedge apples, hedge balls, or monkey balls. These fruits typically measure 8 to 15 centimeters (3 to 6 inches) in diameter and ripen to a bright yellow-green color in the fall. When cut or damaged, the fruit and other parts of the tree exude a sticky, milky white sap.
The Osage orange tree is a small deciduous tree or large shrub, generally growing 8 to 15 meters (30 to 50 feet) tall. Native to a small region of the south-central United States, specifically parts of Oklahoma, Texas, and Arkansas, it has since become widely naturalized across the United States due to its historical use as a natural fence or hedge row before the advent of barbed wire. Its strong, rot-resistant wood was also prized for making bows.
Toxicity and Health Implications
Despite their common name and appearance, horse apples are considered to have very low toxicity to humans and common livestock. While not poisonous, consuming the fruit is not recommended because of its woody pulp, dense texture, and bitter taste, which make it largely inedible. Ingesting large quantities can lead to mild gastrointestinal upset, such as nausea, vomiting, or stomachache in humans.
For animals, particularly horses, the primary concern with horse apples is not severe poisoning but rather the risk of choking due to the fruit’s large size and dense nature. While livestock feeding studies have shown no significant chemical problems, the fruit can become lodged in an animal’s esophagus, potentially leading to suffocation. Dogs and cats may experience mild gastrointestinal discomfort if they ingest the fruit, similar to human reactions, but serious health consequences are uncommon.
Responding to Potential Exposure
Should skin irritation occur from contact with the milky sap of a horse apple, it is advisable to wash the affected area thoroughly with soap and water. This simple action can help mitigate any discomfort or rash that may develop.
If a human, especially a child, ingests a horse apple, it is important to monitor for symptoms like gastrointestinal upset. While severe poisoning is unlikely, seeking medical attention is prudent if large quantities are consumed, symptoms are persistent or severe, or if there is lingering concern. For pets, contacting a veterinarian is recommended if they consume a significant amount of the fruit, show signs of distress, or if there is a concern about a choking hazard. Observing the animal for changes in behavior or digestion is key. To prevent exposure, especially in areas where Osage orange trees are prevalent, it is helpful to keep children and pets away from fallen fruits, particularly if they are prone to putting objects in their mouths.