It may commonly be associated with witchcraft but hemlock is no work of fantasy and is in fact a very real threat in Cornwall's hedges.

Following on from the Packet's feature on the differences between cow parsley, the harmless hogweed and its altogether more poisonous relation giant hogweed, a reader got in touch to warn about hemlock also.

Read more: Difference between cow parsley, hogweed and giant hogweed

This is another plant with an umbrella-like head of small white flowers, which also bear more than a passing resemblance to cow parsley but can be deadly.

Chris Sawle said: "It grows all over Cornwall, looks even more like cow parsley than hogweed and causes paralysis if ingested."

The poison in it can disrupt the central nervous system - a small dose can cause respiratory collapse and in the most serious cases can result in death.

Falmouth Packet:

Hemlock

The Wildlife Trusts describes it as "a notoriously poisonous plant," which can be found in damp places, such as ditches, riverbanks and waste ground but also roadside verges.

It can grow to up to two metres tall and is most commonly found in June and July.

The charity states on its website: "A poisonous plant, hemlock has a repellent smell when its leaves are crushed, helping to ensure that accidental poisonings don't occur very often - even livestock studiously avoid it.

"A tall, upright plant, hemlock can be distinguished by the distinctive and unpleasant, mousy smell of its foliage and its purple-spotted stems. Its leaves are finely divided and large, and its flowers are small and white and appear in umbrella-like clusters.

Characterised by umbrella-like clusters of white, frothy flowers, cow parsley is a familiar sight along roadsides, hedgerows and woodland edges and can grow up to one metre tall.

As previously reported, cow parsley is has large, flat umbrellas of small, white flowers, and large, fern-like leaves.

Falmouth Packet:

Cow parsley

The Wildlife Trusts describes it as: "A hollow-stemmed, tall plant that grows rapidly in the summer before dying back.

"It likes shady habitats in particular, and can be found decorating woodland edges, roadside verges and hedgerows with masses of frothy, white flowers.

When crushed between the fingers, the leaves produce a strong, aniseed-like scent.

One of several common members of the carrot family, this is the most abundant, and the earliest-flowering of the plants known as umbellifers.

There are a number of myths and legends surrounding hemlock, in addition to it being a witch's favourite.

According to Christian mythology, the hemlock plant became poisonous after growing on the hillside of Jesus' crucifixion. When his blood touched the plant, it turned forever toxic.

Hemlock’s most famous victim was the Greek philosopher Socrates, who was sentenced to death for asking philosophical and ethical questions of his students.

Hemlock was commonly used in Greece for executing the condemned and Socrates was ordered to consume a drink made from it.