Is Black Bryony Poisonous? Toxicity Guide for a Toxic Hedgerow Plant

Black bryony is toxic to people, dogs, and cats. Every part of the plant (Dioscorea communis, formerly Tamus communis) is poisonous - leaves, rhizome, and berries. The bright red berries are the most dangerous because they are visually striking in hedgerows in autumn and can attract children and foragers who do not recognise the plant. Even touching the berries or rhizome can cause skin irritation. Do not eat any part of this plant, and do not let children or pets near the berries.

What Makes Black Bryony Toxic?

The plant contains several irritants working together: calcium oxalate raphides (microscopic needle-like crystals), saponins, and histamines. The calcium oxalate crystals penetrate mucous membranes and skin, causing immediate burning and pain on contact. The saponins and histamines compound the irritation and contribute to the systemic effects that occur with larger ingestion.

There is no part of black bryony that has a history of safe food use.

Where Black Bryony Grows

Black bryony is a climbing plant native to Europe, North Africa, and western Asia. It is common in hedgerows, woodland edges, and scrubland across the UK and much of western Europe. The plant produces small greenish-yellow flowers in spring, followed by clusters of berries that ripen to bright red in autumn. The berries persist on bare twisting stems into winter and remain toxic throughout.

It is not related to white bryony (Bryonia dioica) despite the similar name - though white bryony is also toxic.

Symptoms of Black Bryony Poisoning

Dogs and cats: Burning and blistering of the mouth, excessive drooling, vomiting, and diarrhea. Skin contact with berry juice or rhizome sap causes contact dermatitis from the calcium oxalate crystals. Large ingestion can cause hemorrhagic (bloody) GI symptoms and significant distress.

Humans and children: Eating even a small number of berries - fewer than 10 - causes burning and pain in the mouth and throat, followed by vomiting and diarrhea. Larger amounts produce hemorrhagic gastroenteritis, significant fluid loss, and potentially kidney failure. Skin contact with berry juice or rhizome sap causes contact dermatitis, sometimes with blistering, from the calcium oxalate crystals penetrating the skin. Symptoms from ingestion typically appear within 30 minutes to a few hours.

What to Do

If someone ate black bryony berries:

1. Do not induce vomiting.
2. Call poison control immediately at 1-800-222-1222 (US), or in the UK contact the NHS 111 helpline.
3. If a child swallowed berries, seek emergency medical care - do not wait for symptoms to appear.
4. Bring a sample of the plant or berries if possible, for identification at the clinic.

If a pet ate the berries:

1. Call your vet or ASPCA Poison Control at 888-426-4435 immediately.
2. Watch for drooling, vomiting, and signs of distress.
3. Keep a sample of the plant if possible for identification.

For skin contact:

1. Wash the affected area thoroughly with soap and water.
2. Avoid rubbing the area, as friction can drive calcium oxalate crystals deeper into the skin.
3. Seek medical care if blistering or significant irritation develops.

Identifying Black Bryony

Black bryony is most dangerous to people who do not recognise it. Key identification features:

• Bright red berries in dense clusters along twining stems
• Heart-shaped, glossy leaves
• Climbs and twines through other hedgerow vegetation
• Common in UK and European hedgerows, particularly in autumn when berries ripen

The berries have never been used as food. Any bright red hedgerow berry you cannot positively identify should be treated as toxic.

Keeping Pets and Children Safe

• Teach children not to eat any berries from hedgerows or unfamiliar garden plants.
• When walking dogs in areas where black bryony grows, be alert to berry clusters on fallen or low-trailing stems.
• Do not use black bryony stems or berries in decorative autumnal wreaths or arrangements if children or pets have access to them.
• Wear gloves when handling the plant during garden clearance, and wash hands and any exposed skin afterward.

Frequently Asked Questions

Are black bryony berries deadly? Potentially yes in large amounts. Small ingestion in a healthy adult causes severe, painful GI symptoms. Large ingestion can lead to kidney failure. Children are at much higher risk due to lower body weight. Treat any ingestion as a medical emergency.

Is black bryony found in the US? Black bryony is primarily a European plant and is not a common hedgerow species in North America. It may occasionally appear as an ornamental or escaped plant. Related Dioscorea species (yams and their relatives) occur in North America with their own toxicity profiles.

What does black bryony look like in autumn? In autumn the plant is most recognisable from its clusters of bright red berries on twining stems draped through hedgerows. The leaves may be yellowing by then. The berries are the most striking and most dangerous feature at this time of year.

Can black bryony be confused with bittersweet nightshade? Both produce red berries on climbing or sprawling stems in hedgerows. Bittersweet nightshade (Solanum dulcamara) has distinctive purple and yellow flowers when in bloom, and its berries often show a mix of green-to-yellow-to-red on the same cluster. Both are toxic. When in doubt, do not touch or eat any plant you cannot positively identify.

Does touching the berries cause immediate pain? Yes. The calcium oxalate crystals in the skin of the berries can cause burning and irritation on contact. If you have handled the berries, wash your hands with soap and water immediately.