Corncockle codswallop

On 16 July 2014, the national news media pounced on a report that a National Trust warden in Sunderland had stumbled across a poisonous plant that was thought to be extinct in the wild. News items described the corncockle (Agrostemma githago) as “pretty, but deadly” and stated that it is “highly toxic if it is broken or eaten”.

Then, on 26 August 2014, the media wallowed in a story about the BBC’s Countryfile programme sending out thousands of free packs of wildflower seeds that included this lethal species. Apparently some had been planted in a public park in Royal Wootton Bassett, but the plucky town council leapt into action and ordered the immediate destruction of these noxious triffids.

What a load of scaremongering codswallop!

Corncockle has for many years flourished in gardens and parks across the UK, with no evidence that it has caused serious toxicity. Britain’s commercial seed suppliers promote it heavily as a “cottage garden” flower, usually without mentioning any health risk.

And where is the evidence of a poisoning risk? Corncockle certainly contains toxins, but so do numerous other denizens of our parks and gardens. The Royal Horticultural Society lists some 120 potentially harmful garden plants, many of which are widely grown. However, it insists that all these plants are safe if treated with respect.

Corncockle’s toxic saponins are at their highest concentration in its seeds. But anyone tasting the seeds, which are rock hard and bitter, would be likely to spit them out immediately. Swallowing a few seeds may lead to vomiting or stomach pains, but not serious toxicity.

This allegedly lethal plant has even had its medicinal uses. It was once employed to treat jaundice, oedema, gastritis and constipation. Powdered seeds were mixed with honey for use as a diuretic, expectorant and anthelmintic. In Wales, the 12th century Physicians of Myddfai included corncockle in a medley of herbs used as a remedy for pneumonia. And in continental Europe the seeds have been used in folk medicine for tumours, warts and abscesses.

So just don’t believe everything you read in the popular news media. 

Last updated
The Pharmaceutical Journal, Corncockle codswallop;Online:DOI:10.1211/PJ.2014.20066349

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