The beautiful alstroemeria, also known as Peruvian lily or lily of the Incas, is native to the Andes. This tuberous perennial bears orange or yellow blooms, with hybrid varieties available in a wider range of colors. In the United States, the flower is hardy to Zone 7, but it requires winter protection. This plant's lovely appearance, however, belies its toxicity: All species of alstroemeria—especially cut or damaged parts—must be handled with care.
Every part of the alstroemeria can be toxic. The cause of this toxicity is the compound tulipalin, which is produced when plant tissues are damaged—for example by a cut. The sap of the alstroemeria plant contains the compound Tuliposide A, whose enzymes produce the allergen, according to the Botanical Dermatology Database.
Tulipalin is a contact allergen, which means it causes a reaction on touch, as well as an ingested allergen, causing a reaction if swallowed. The California Poison Action Line lists alstroemeria in both Category 2 and Category 4. Category 2 toxins have "mild toxicity," meaning that if ingested these substances, including alstroemeria, can "cause minor illnesses such as vomiting or diarrhea." Category 4 toxins cause dermatologic—skin—reactions, such as "a skin rash or irritation." Further effects can include blisters, skin fissures or eye irritation.
Because any part of the alstroemeria plant can cause a reaction, gardeners may experience a reaction from such everyday handling as transplanting bulbs or cutting flowers. To be safe, wear plastic gloves when working with alstroemeria; ordinary cloth gardening gloves may allow the irritant, tulipalin, to reach your skin. Remove gloves as soon as you are finished, and wash your hands in warm, soapy water; be careful not to touch your face, especially your eyes or mouth, until you have done so.
If anyone ingests any part of the alstroemeria, call your local poison control hotline or your physician immediately. In cases of skin contact, wash the affected skin immediately and call poison control or your physician for a recommendation of a specific response based on the symptoms.
While humans may take precautions to avoid contact with the toxins in alstroemerias, pets are at particular risk for accidental ingestion. The California Poison Action Line advises that most plants toxic for humans are also toxic for animals.