Dangerous Plant
Toxic in Sunlight: What Giant Hogweed Causes and How to Identify It
Giant Hogweed, also known as Heracleum, is invasive: It was brought to Europe as an impressive ornamental plant from the Caucasus at the end of the 19th century. Since then, it has spread, growing in meadows, along riverbanks, and at the edges of paths. What many do not know: It is toxic.
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Its feathery flowers invite to be picked, its tall stems for playing hide and seek – but when the sun shines, the Giant Hogweed becomes toxic. Recently, 17 people in Essen had to be treated for burns after the “Mammoth March NRW.” But not only the invasive species is dangerous; its native cousin is as well.
Almost no poisonous insects and snakes, hardly any wild animals, and natural disasters are also very rare: Nature makes it relatively easy for us in Central Europe. One can easily forget that dangers lurk here as well. Like with Hogweed: This plant caused burns to more than a dozen people during a 24-hour race in Essen, and some even had to go to the hospital.
What Happened?
According to reports, there was a large-scale operation by the fire brigade and emergency doctors on Sunday in Essen’s Grugapark. Several participants of the “Mammoth March NRW” dragged themselves across the finish line and headed directly for the medical service that called for reinforcement. In total, 17 people were affected, showing burn-like symptoms. Five of them were treated further in the hospital. The fire department suspects that they came into contact with Giant Hogweed while running.
The native Meadow Hogweed is also toxic. Like the Giant Hogweed, its plant sap contains furanocoumarins that are phototoxic. This means: Their burning effect only manifests under sunlight. However, the Meadow Hogweed is much smaller than its gigantic cousin and also less dangerous.
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How Toxic is Hogweed?
Giant Hogweed originally comes from the Caucasus but has been spreading here since the end of the 19th century. The plant is invasive: it displaces native flora and now grows in many places in meadows, along riverbanks, and at the edges of paths and forests. From spring to autumn, the powerful plant can be admired here – but better from a distance: Its flower sap contains furanocoumarins, which are phototoxic. This means they become toxic in sunlight and strip the skin of its natural UV protection. The consequences can range from skin irritations to first, second, or even third-degree burns, sometimes even days after actual contact.
What is less known: The common Meadow Hogweed can also be toxic and cause skin irritations and swelling, especially in bright sunshine. However, the native plant is much smaller and contains less furanocoumarins. Therefore, the consequences of contact are less severe than those of its gigantic cousin. On the contrary, it has even been used as a medicinal plant in the past.
How to Identify Hogweed?
The shape of both species – Giant and Meadow Hogweed – is very similar: small white flowers arranged in umbels and angular, hairy hollow stems. Both also do not smell very pleasant. However, the Giant Hogweed, also called Heracleum, grows several meters high, and its umbels can reach a diameter of up to 50 centimeters. The stems sometimes show red spots, and the leaves appear longer than those of the Meadow Hogweed.
What to Do If You Come into Contact?
Hogweed is a pretty plant: The feathery flower crowns invite you to brush by while walking, and children are tempted to play hide and seek among the tall stems. Both should be avoided: The best protection against the phototoxic plant sap is to avoid all contact. If you do get contaminated, “direct sunlight on uncovered skin areas should be prevented,” warns the Coordination Center for Invasive Neophytes in protected areas of Saxony-Anhalt.
Affected skin areas should be washed as soon as possible with soap and water, and the sun should be avoided for a few days. If the symptoms are severe, a visit to the doctor is the only solution.