The term “lily” is frequently used to describe a wide variety of flowering plants, making the question of their toxicity complicated. Many plants sharing this common name belong to different botanical families and contain vastly different chemical compounds. Understanding the specific genus of the plant is paramount to assessing the actual risk of poisoning. This distinction determines whether accidental ingestion results in mild discomfort or a serious medical emergency.
Toxicity Levels of True Lilies (Genus Lilium)
True lilies belong to the Lilium genus, including common varieties like the Easter Lily, Tiger Lily, and Oriental Lily. While these plants are infamous for causing acute kidney failure in cats, their toxicity profile in humans is generally much lower. Ingesting parts of a true lily typically results in minor gastrointestinal irritation.
Symptoms for humans are usually limited to digestive upset, such as nausea, vomiting, or diarrhea. For a healthy adult, consuming a small amount is unlikely to cause severe systemic effects. The bulbs of some Lilium species are even consumed in Asian cuisine when properly prepared.
Highly Toxic Plants Commonly Called Lilies
The most significant risk comes from plants that are not true lilies but share the common name, often containing potent toxins. These plants include the Peace Lily (Spathiphyllum), Calla Lily (Zantedeschia aethiopica), and Lily of the Valley (Convallaria majalis).
The Peace Lily and Calla Lily contain insoluble calcium oxalate crystals throughout their tissues. When chewed or swallowed, these needle-like crystals cause immediate, intense pain by mechanically irritating the sensitive mucous membranes of the mouth and throat.
Lily of the Valley presents a different, potentially more severe, danger because it contains cardiac glycosides, primarily convallatoxin. These compounds interfere with the heart’s ion channels, affecting its rhythm and force of contraction. Ingestion of any part of this plant, especially the berries or roots, can lead to serious cardiovascular problems.
Symptoms of Accidental Ingestion
The physical reactions to accidental ingestion vary based on the specific toxins involved. Exposure to the calcium oxalate crystals found in Peace Lilies and Calla Lilies causes an immediate burning sensation in the mouth, lips, and tongue. This irritation can quickly lead to swelling, increased saliva production, difficulty swallowing, and temporary hoarseness. The immediate pain often discourages a person from consuming a dangerous quantity.
Ingestion of Lily of the Valley can result in initial gastrointestinal symptoms and delayed, life-threatening effects. Initial symptoms may include nausea, vomiting, abdominal pain, and diarrhea. More concerning are the cardiac symptoms, which include a slow or irregular heartbeat, hypotension, and the potential for cardiac shock in severe cases. The effects of cardiotoxins can also manifest as confusion or fainting.
Immediate Steps Following Exposure
If accidental ingestion or contact with a suspected toxic plant occurs, the first step is to remove any remaining plant material from the mouth. Gently wiping the mouth with a cold, wet cloth or having the person rinse and spit with water can help clear the area. If a person has skin or eye exposure, the affected area should be rinsed thoroughly with water for at least 15 to 20 minutes.
It is imperative to contact Poison Control immediately by calling the national toll-free hotline at 1-800-222-1222 for expert guidance. Do not wait for severe symptoms to develop before making the call. Be prepared to provide the person’s age, weight, and the name or description of the plant involved, which helps determine the precise level of risk. If the person collapses, has difficulty breathing, or shows signs of an irregular heartbeat, emergency services should be contacted without delay.