Lily of the Valley Poisoning

Medically Reviewed by Mahammad Juber, MD on December 16, 2022
5 min read

Sometimes, the most unassuming plants can be the most dangerous. Lily of the valley is a plant that grows small, demure white bell flowers that are often used in gardens and in bouquets. Beneath the sweet exterior of these plants lies a secret: the plants are highly toxic and can cause severe illness and death. 

Lily of the valley (Convallaria majalis) are common garden flowers that also make a good ground cover. They grow in the northern hemisphere across the United States, Europe, and Central Asia. These pretty perennials bloom in April and May and grow in dense groups.

Lily of the valley is hearty, making it a popular garden flower. It can grow in most of the U.S. and does well in the shade of trees and shrubs. Lily of the valley is also growing in popularity as a cut flower, especially in bridal bouquets.

Lily of the valley isn’t actually a lily. It’s from the Asparagaceae family, which, as the name suggests, also contains asparagus.

Throughout history, the lily of the valley has popped up in stories and mythology. Lily of the valley can be found in Greek, Roman, and German myths, and is mentioned in the Bible fifteen times. Historically, the lily of the valley has represented chastity, humility, motherhood, sweetness, and purity. The lily of the valley is sometimes called the May lilly, and is the birth flower for the month of May, as this is when the flowers often bloom.

Lily of the valley contains compounds that can be used medicinally. For example, one compound, convallatoxin, can be used to help treat certain heart problems. Most convallatoxin used in medication is made in a lab, not from the plant.

Lily of the valley is well known for its small, bell-shaped white flowers. These flowers grow out of a stem that grows 8-12 inches tall. The flowers grow in a vertical clump, or raceme, with five to ten flowers, on one side of the stem. Sometimes, the flowers are pale pink. The flowers of the lily of the valley have a strong floral scent.

The leaves of the lily of the valley plant are smooth, green, and vary in size from elliptical to oblong. The leaves grow low on the stem and overlap to surround it, offering protection.

In the fall, the lily of the valley plants may grow berries. These berries are small, smooth, and reddish-orange. Each berry has one to six seeds.

The lily of the valley plants are extremely toxic. All parts of the plant can cause illness when eaten. It is categorized as having major toxicity.

The lily of the valley contains several compounds that can affect the heart. It may be used in very small quantities in medication, but ingesting the plant can lead to severe illness, cardiac distress, and even death.

The roots of the flower contain the most amount of poison, but poisoning cases are most often the result of children eating the berries. Some people may experience a rash or skin irritation from touching the plant.

While the compounds in the lily of the valley mainly attack the heart, lily of the valley poison effects can ravage the whole body.

Cardiac symptoms. Lily of the valley affects your heart, causing it to pump more slowly and forcefully. Lily of the valley poison symptoms of the heart include:

  • Fainting
  • Irregular heartbeat (arrhythmia)
  • Slow heartbeat

Gastrointestinal symptoms. Gastrointestinal symptoms caused by eating lily of the valley include:

  • Diarrhea
  • Excessive urination at night
  • Loss of appetite
  • Nausea
  • Stomach pain
  • Vomiting

Nervous system symptoms. Lily of the valley can also affect the nervous system. If you eat lily of the valley, you may experience:

  • Confusion
  • Depression
  • Disorientation
  • Drowsiness and lethargy
  • Headache
  • Overall weakness

Vision symptoms. Lily of the valley may impact your vision and lead to symptoms such as blurry vision or seeing halos around objects.

Depression, loss of appetite, and halos in your vision are usually only present in cases of chronic overdose.

Skin symptoms. Touching lily of the valley may lead to skin irritation. This can cause symptoms like:

  • Bumps
  • Blisters
  • Itching
  • Red rash or patches
  • Swelling

If you discover you or a loved one have ingested lily of the valley, seek immediate medical help. You can contact poison control on their website or by calling their toll-free hotline at 1-800-222-1222. When you talk to poison control, they’ll want to know:

  • The age of the person who swallowed the plant
  • The weight of the person who swallowed the plant
  • Current symptoms and condition of the person who swallowed the plant
  • What part of the plant was swallowed
  • How much of the plant was swallowed
  • What time the plant was swallowed

Because the lily of the valley is so toxic, poison control will likely recommend you visit a hospital for medical care. At the hospital, your care team will monitor your vital signs like breathing, blood pressure, and heart rate. Lily of the valley poisoning treatment may include activated charcoal to absorb the poison, medications to push the poison through your digestive system, intravenous fluids, and/or medications to counteract some of the poisonous compounds. You may also be given medications to reduce the symptoms of lily of the valley poisoning such as irregular heartbeat.

Symptoms of the lily of the valley poisoning usually last from one to three days. You may need to stay in the hospital during this time. With proper medical care, death is unlikely.

Lily of the valley plants produce very distinct-looking flowers, and there aren’t any plants that are easily mistaken for the lily of the valley. The plant that is most similar is perhaps white mountain heather. These plants have small, white, bell-like flowers similar to the lily of the valley. The flowers of white mountain heather have a red base and reddish stamen, and the stems are covered in scale-like leaves. White mountain heather is a shrub that grows best at high altitudes. Unlike the lily of the valley, it’s not toxic.