Lilies are a common sight in gardens and homes, admired for their diverse beauty. Concerns often arise regarding their potential toxicity, particularly their pollen, to humans. While often a concern, lily pollen itself is generally not considered toxic to humans in the same way it is to pets. However, other parts of the lily plant contain compounds that can cause symptoms if ingested.
Understanding Lily Plant Components and Toxicity
The term “lily” encompasses a variety of plants, and their toxicity to humans can differ significantly. True lilies, belonging to the Lilium genus, include popular varieties like Easter lilies, Asiatic lilies, and Tiger lilies. All parts of these true lilies, including the leaves, stems, flowers, and roots, contain compounds that can be harmful if ingested by humans. While the specific toxic substance in true lilies is not always fully identified, ingestion can lead to various symptoms.
In contrast, plants often referred to as “lilies” but not true lilies, such as daylilies (Hemerocallis species), peace lilies (Spathiphyllum species), calla lilies (Zantedeschia species), and lily of the valley (Convallaria majalis), have different toxic profiles. Peace lilies and calla lilies contain insoluble calcium oxalate crystals in all their parts. These needle-shaped crystals cause immediate irritation upon contact or ingestion. Daylilies are generally considered safe for humans.
Lily of the valley (Convallaria majalis) is a particularly potent plant, containing cardiac glycosides like convallatoxin. All parts of this plant are highly toxic and can lead to severe illness or even death if ingested, affecting the heart and other bodily systems. Unlike the irritant effects of calcium oxalates, the compounds in lily of the valley directly impact heart function.
The pollen from true lilies, while a common allergen for some individuals, is not typically considered a direct toxin when ingested by humans. However, the primary concern for human exposure to lilies stems from the ingestion of plant material. The sap from certain lilies, including true lilies, calla lilies, and lily of the valley, can also cause skin irritation upon contact.
Recognizing Symptoms and Taking Action
If a person ingests parts of a lily plant, the symptoms can vary depending on the type of lily and the amount consumed. For true lilies or those containing calcium oxalate crystals like peace lilies and calla lilies, immediate symptoms often include oral and gastrointestinal irritation. This can manifest as a burning sensation in the mouth, throat, and lips, along with swelling, increased saliva production, nausea, vomiting, diarrhea, and stomach pain.
Skin contact with the sap of some lilies can lead to irritation, redness, rashes, or hives. While severe, life-threatening poisoning from true lilies or calcium oxalate-containing lilies is uncommon in humans, significant oral swelling could potentially affect speaking or swallowing. In cases of ingestion of highly toxic non-true lilies, such as lily of the valley, symptoms can be much more severe, including irregular heartbeat, confusion, and drowsiness.
If ingestion or significant contact with a lily occurs, take immediate action. For oral exposure, rinse the mouth thoroughly with water. Offering sips of cool liquids like milk or ice chips can help soothe burning. If skin irritation develops, wash the affected area well with soap and water. It is recommended to contact a poison control center (1-800-222-1222) or seek medical attention, especially if symptoms are severe, persistent, or if a significant amount was ingested. Do not induce vomiting unless specifically instructed by a healthcare professional.
Preventing Exposure
To minimize the risk of accidental exposure to lilies, particularly in households with children, take preventative measures. Placing lily plants, whether potted or in floral arrangements, out of reach. This includes positioning them on high shelves or in rooms that are inaccessible to young children.
It is also important to educate children about not eating or touching unknown plants. Promptly cleaning up any fallen lily petals, leaves, or pollen is also a good practice, as these can be transferred to hands and then to the mouth. After handling lily plants, wash hands thoroughly with soap and water. When gardening, wearing gloves can provide additional protection against skin contact.