The berries of plants belonging to the Hypericum genus, such as St. John’s Wort (Hypericum perforatum) and its ornamental relatives, are not considered safe for consumption. These attractive fruits should be treated as non-edible and potentially toxic to humans and pets. While the degree of toxicity varies significantly between the numerous species, ingesting any part of the plant, especially the berries, carries a risk of adverse health effects due to naturally occurring toxic compounds.
Identifying Common Hypericum Species
The Hypericum genus includes a wide array of plants, from the well-known medicinal herb Hypericum perforatum to popular ornamental varieties frequently used in floral arrangements. H. perforatum plants produce seed capsules that are often mistaken for berries, typically turning a dark brown color as they dry. These plants are characterized by their bright yellow, five-petaled flowers and small leaves that appear to have translucent perforations when held up to the light.
Ornamental species, such as Hypericum inodorum and Hypericum androsaemum (Tutsan), are cultivated for their visually striking fruit. These true berries are small, vibrant, and range in color from pale green and yellow to deep red or nearly black. Because the appearance of Hypericum fruit varies widely, relying on visual characteristics for safe identification is unreliable. These ornamental types are a common source of accidental ingestion when brought indoors in decorative bouquets or garden displays.
The Chemical Basis of Toxicity
The primary danger associated with consuming Hypericum berries stems from a group of compounds known as naphthodianthrones, with hypericin being the most recognized. Hypericin is a naturally fluorescent red pigment concentrated in the plant’s leaves, flowers, and fruit. It is this compound that acts as a potent photosensitizer when ingested.
Once absorbed into the bloodstream, hypericin circulates throughout the body and accumulates in the skin and eyes. The mechanism of toxicity is activated upon exposure to ultraviolet or visible light. When light energy strikes the hypericin molecules, they generate highly damaging reactive oxygen species. This process, known as phototoxicity, leads to oxidative damage on a cellular level, particularly in tissues exposed to sunlight. The resulting effect is delayed and dependent on subsequent light exposure.
Immediate Effects and Safety Measures
Ingestion of Hypericum berries typically results in immediate gastrointestinal distress. Symptoms may include nausea, vomiting, stomach cramps, and diarrhea. With larger consumption, individuals may also experience more pronounced symptoms such as dizziness, confusion, or abdominal pain. These effects often manifest shortly after the berries are eaten.
A more serious, often delayed, effect is the phototoxic reaction caused by circulating hypericin. If exposed to sunlight after ingestion, the person or animal may develop severe skin inflammation, a rash, or blistering, akin to a severe sunburn. This reaction can take one to two days to appear following consumption. For any suspected ingestion by a child or pet, immediately remove any remaining plant material from the mouth and seek professional medical advice. Contacting a local poison control center or emergency medical services is the proper protocol, and securing a small sample of the berry can assist medical staff with identification.