Revered and feared, but a spectacular plant to look at…

Giant hogweed – Heracleum mantegazzianum is often talked about, seldom seen in the flesh let alone appreciated for its statuesque beauty. Many bush crafters and foragers, will be much better acquainted with hogweed – Heracleum sphodylium its smaller and more useable little brother. They are both in the Apiaceae family which is not only a source of amazing edible plants but contains many of the deadly plants in Britain too, namely Hemlock and Hemlock water dropwort. In this blog I am going to focus on how appreciating the qualities of Giant Hemlock can bring us closer to nature and help educate us in enjoying this spectacular plant.

Giant hogweed – Heracleum mantegazzianum

Giant Hogweed is a non-native invasive, monocarpic, perennial, that flowers in early summer. This year It was in full flower at the beginning of June. It is native to the Caucasus mountains and central Asia. The flower heads are made up of multiple flowers on stems that produce a flattened, umbrella shaped, many flowers head. The old name for this family was the umbelliferae.

Flattened, umbrella shaped, many flowers head

So how did it manage to get to Britain I hear you ask?

Well, it was introduced in the 19th Century as an ornamental garden plant. It was used in damp settings in large garden collections but escaped and naturalized in the wild. It is thought that this happened due to the seeds being transported by water. Once established it is very difficult to remove due to the qualities we will explore later in this blog.

The leaves are much larger than hogweed and serrated rather than rounded. The stems are hairy, blotched, and sinister looking.

Young foliage is pale green

The image above was taken in early spring when the young foliage is pale green, but as the season develops the leaves get darker in colour and the stems elongate as the plant grows. Mature plants can reach between 2 and 3 metres in height and up to 2 metres in spread.

Older foliage is a drker green

As mentioned above they love a damp, waterside habitat to grow happily. From a bushcraft perspective they are an indicator of water species and as such that is another good reason to get familiar with this plant.

They love a damp, waterside habitat

The image above is from a wet ditch on a countryside verge. Despite it having been very hot for weeks the ditch was full of water and thus a perfect habitat for this magnificent plant.

So why has this plant got such a bad reputation and is it justified?

It most certainly is justified. The sap from the stems contains furocoumarin which induce blistering of the skin (phytophotodermatitis) when exposed to sun light. The blistering can be bad in the first instance, but can recur when exposed to ultra violet light over many months and in the most serious cases over many years.

A young person’s hand blistering up

The above photo is of a young person’s hand blistering up. It is also worth noting that dogs can get effected too.

Typically ground works strimming overgrown areas who are unfamiliar with the dangers of this plant cut into the stems with their machines and spread the sap onto the skin.

The message is avoid any sap on the skin at all costs. Even brushing past an exposed part of the plant or breaking as you push past is enough to get the sap on the skin. The current guidelines if you accidentally come in contact is to wash the contact zone as soon as possible and seek medical advice whilst remaining out of sunlight.

In parts of the Britain, it has become an invasive species and is colonizing huge areas of our waterways. There are numerous methods of control from cutting off the flowers before they seed, spraying with Glyphosate, digging up plants to experimenting with sheep grazing to reduce colonies.

Avoid any sap on the skin at all costs

There is no question in my mind that it is a plant to get more familiar with in your local environment. Observation and being present to notice this spectacular looking, sinister plant could avoid very serious skin blistering.

My children spend a lot of time fishing at this time of year and it is a plant that I am very keen that they become familiar with. So, make sure that you spread the message about this plant to your young people. Make it an opportunity to be respectful of nature and engage with noticing the plants on their adventures this summer.

Spread the message about this plant to your young people


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