Several trees found across the UK contain toxins that can be harmful to humans if ingested. While some are native, others are commonly planted garden and park ornamentals [1, 2, 3, 4, 5]

The significant poisonous trees to be aware of include the following:

 

• Common Yew (Taxus baccata): This tree is considered one of the most toxic woody plants. Nearly all parts of the tree, including the bark, needles, and seeds, contain taxine alkaloids. Ingestion is a serious medical emergency and requires immediate professional intervention. [1, 2]
• Laburnum (Laburnum anagyroides): Often called the "golden chain tree". It contains the toxin cytisine. Ingesting the seeds, pods, or bark can cause severe gastrointestinal distress and neurological symptoms. [1, 2, 3, 4, 5]
• Holly (Ilex aquifolium): The bright red berries can cause severe vomiting, diarrhoea, and drowsiness if ingested. [1, 2, 3]
• Elder (Sambucus nigra): The uncooked berries, raw leaves, and bark contain cyanogenic glycosides. Consuming raw parts of the plant can cause nausea and gastrointestinal distress. [1, 2]
• Horse Chestnut (Aesculus hippocastanum): The bark, leaves, flowers, and raw conkers contain toxic saponins. Ingestion can lead to severe gastrointestinal issues. [1]
• Spindle (Euonymus europaeus): This native shrub produces pink berries that contain alkaloids. Ingestion can cause intense abdominal pain and vomiting. [1, 2, 3]
• Buckthorn (Rhamnus cathartica): All parts, especially the bark and berries, contain purgative toxins that can lead to painful gastrointestinal symptoms. [1, 2, 3]

 

Accidental poisoning is a risk when individuals, particularly children, interact with fallen seeds or berries. For official guidance on potentially harmful plants, the Royal Horticultural Society provides comprehensive safety advice. [1]