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Cynoglossum officinale, hound’s tongue


A visually attractive plant with a most unpleasant smell containing compounds capable of causing liver failure if ingested over a long time.



Cynoglossum officinale, hound’s tongue

Cynoglossum officinale, hound’s tongue

Meaning of the Name

It’s English name ‘Hound’s tongue’ is said to come both from the texture of the leaves and the smell of the plant. The Latin comes from a corruption of the Greek words ‘kynos’ meaning dog and ‘glossa’ meaning tongue.
From the Latin for workshop or office and, thus, given to the species of a plant which was sold in shops or pharmacies and, by extension, a useful plant.

Common Names and Synonyms

hound’s tongue

How Poisonous, How Harmful?

The toxic components are pyrrolizidine alkaloids called cynoglossine, consolidine, echinatine and heliosupine. Prolonged ingestion of pyrrolizidine alkaloids leads to liver damage and eventual failure and the plant is more a threat to farm stock than humans.


All reported incidents refer to cattle or horses. No cases of human poisoning have been found.

It is interesting to note that, although the plant contains PAs and has been known to cause fatal poisoning in horses and cattle, there is not the same hysteria about it as there is about Jacobaea vulgaris (syn. Senecio jacobaea), common ragwort.

Folklore and Facts

The smell of the plant resembles dogs' urine so travellers would put some in their shoes to ward off dogs as they walked along.

The 16th century book entitled ‘the boke of secretes of Albertus Magnus of the vertues of Herbes, Stones and certaine beastes’, says that hound’s tongue attached to a dog’s neck where he cannot reach it with his mouth will lead the dog to turn in circles until he falls down dead. The author insists that ‘this has been proved in our tyme’.

Rabbits are supposed to be able to eat the plant without harm and, until myxomatosis reduced the rabbit population, they kept it in check. Since the liver damage it causes may be a long time in appearing it is by no means certain that it is completely harmless to rabbits.

In the 16th century, the roasted root were used as a suppository to cure haemorrhoids. The juice of the boiled leaves mixed with pigs’ grease, used as an ointment, prevents hair loss.