Who, what, why: How dangerous is Devil's Helmet?

Aconitum Image copyright Thinkstock

A gardener died after apparently coming into contact with Aconitum, a poisonous plant known as Devil's Helmet. How dangerous is it, asks Tom Heyden.

"It's probably the most poisonous plant that people will have in their garden," says poison expert John Robertson. Aconitum, part of the buttercup family, goes by various nicknames depending on the exact species - Monkshood, Wolfsbane, the Queen of Poisons, or Devil's Helmet. Its reputation for death goes all the way back to the mythical Greek dog Cerberus, from whose saliva the plant supposedly grew.

The roots are its most poisonous part. If ingested, the toxicity acts quickly. "It tends to cause violent vomiting and diarrhoea - then death follows fairly quickly from heart failure," says Robertson, who edits the Poison Garden website. Most fatalities occur within a few hours, he says. The leaves are less toxic. One couple told him how they'd planted Devil's Helmet to brighten up their herb garden but received severe stomach upsets after accidentally picking some for a salad. It's unclear exactly what type of contact may have caused the recent fatality. But merely brushing the foliage is unlikely to cause harm unless someone is unusually susceptible, although absorption through the skin is possible, says Guy Barter, the Royal Horticultural Society's chief horticultural advisor. He recommends wearing gloves for gardening, whether or not there are poisonous plants around.

Aconitum is sold in almost every garden centre and many people will have it in their garden. But despite being extremely poisonous, harmful cases are very rare as few will ingest the roots. "If it were that dangerous then there would be many more cases than we see," Robertson adds.

In 2004, Canadian actor Andre Noble died after accidentally eating some on a hike. But this is unusual; Aconitum looks far less tempting than poison berries, says Robertson. In the past, its deadly toxins used to adorn the tips of poison arrows. And its root extracts have featured in modern murder cases. In 2010, Lakhvir Singh, the "curry poison killer", was jailed for life for lacing her former lover's curry with Indian aconite, known as the Queen of Poisons.

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