Heracleum sphondylium (common hogweed or cow parsnip)

​“Harry waved his wand and shouted “Heracleum Sphondylium!” And from out of the ground a plant began to emerge.” 

I annoyed the kids by stopping at a junction to jump out of the car to take a photo of this hogweed dwarving its neighbouring cow parsley and other wild flowers. An absolutely beautiful specimen, and shows how large common hogweed can get!

​The name Heracleum sphondylium (common hogweed or cow parsnip) sounds like a Harry Potter spell or a line from Monty Python, and this is my ‘hook’ to help me remember the binomial name. Heracleum sphondylium is a bit of a foragers secret, and lives up to its magical name: not only it is feared by many and yet a firm foragers favourite, it is also in the top 10 species for pollinators, being an important foodsource not only for flies, wasps and bees but also for beetles and caterpillars. The name common hogweed is thought to have arisen because hogweed was traditionally used as pig fodder, and because the flowerheads have a distinct farm-like smell which helps to attract pollinators.​ ​

Young hogweed leaves

Common hogweed begins to sprout fairly early in Cornwall thanks to our temperate climate. I like to describe hogweed as tasting like asparagus on steroids, but this description does not do it justice. I have friends who dislike asparagus but adore hogweed. The young leaves are the best part, but do need to be cooked to remove any bitter notes. I particularly like to pair hogweed with eggs, but it also can make a great addition to any dish using greens or stir fries. I was asked to cater for a gin cruise a few years ago, and one of the canapés I created was hogweed frittatas. The aromatic flavour of the hogweed works so well with gin that I received praise on how well my canapés complimented the gins on offer, so I explained that I had created my canapés with this in mind! The young hogweed shoots are delicious made into tempura (we foragers love to tempura everything!), as well as the unopened flower heads that can also be used as a broccoli substitute. The larger leaves we often make into crisps: coat with oil and sprinkle with salt and cook on high for a few minutes (although this can be a bit hit and miss!). ​

Young hogweed leaf at it's best for picking for tempura!

A mature hogweed leaf making this hand look very dinky!

A flourishing example of how hogweed looks right now (late spring).

When hogweed begins to die back the seeds can be collected and used as an aromatic spice. A while ago I gave some hogweed seeds to a chef friend to experiment with and he was blown away by the flavour, he said they tasted just like the Golpar seeds that he uses to spice his curries. I later researched Golpar and discovered that these are the seeds from Heracleum persicum, a hogweed native to Iran and a sister plant to our native Heracleum sphondylium! The roots are edible but as an ethical forager who likes to promote sustainability I only forage the four F’s: fungi, foliage, flora and fruit, as a result I haven’t had the opportunity to dig up common hogweed to sample its roots yet. I understand from others that they are lovely, and I hope to try them soon as I have a few plants which have spontaneously sprung up in my garden (probably from my habit of emptying my basket in the garden after my walks- unfortunately this has also lead to Smyrnium olusatrum (alexanders) springing up everywhere, much to the dismay of my wife who is not a fan!)

Here you can just about make out the young flowering head that looks so similar to broccoli, nestled inside its sheath.

 The fear and controversy over hogweed derives from its triffid-like sibling, Heracleum mantegazzianum (Giant hogweed). The sap of both plants contains furanocoumarins, a chemical that reacts with the ultraviolet in sunlight (hence phototoxic) and this reaction causes phytophotodermatitis, severe burn-like blisters and rashes. Whilst both plants contain furanocoumarins, common hogweed has far lower levels and in all my years foraging I personally have not encountered problems from handling this plant. Giant hogweed, on the other hand, contains very high levels of furanocoumarins and it takes very little exposure of the sap to cause such a bad skin reaction that medical attention is needed. Because of this there is a lot of scaremongering around hogweed and confusion over the differences between the two. Common hogweed is very common! and easily found in hedgerows, roadside verges, the edges of meadows and fields and even in woodland. The chances are that you have walked by this plant many many times. Giant hogweed however is a non-native species that is subject to schedule 9 of the Wildlife and Countryside Act (1981) and is unlikely to be found in the wild here in Cornwall. ​

A mature hogweed with the unopened flowers pink compared to the opened flowers being white. Often the flowers will stay pink, but are more commonly white from bud to opening.

I understand it has escaped from gardens in other parts of the country and has become problematic as specialist teams are needed to remove them. Giant hogweed can often be found near canals and waterbeds, it was popular for a time as an exotic garden plant due to its enormous size, but due to its scarcity here I haven't had the opportunity myself to see this monster in the flesh

A selection of apiaceae leaves. Left to right these are: Heracleum sphondylium (large and small leaves), then Dacus carota, next to Oenanthe crocata with the last 2 leaves being Smyrnium olusatrum (peeking in the edge of the image to the very far right are the flowers of what I think are Conopodium majus).

Flowering hogweed again towering over the other wild plants. Note how the flower head has an umbel shape with the actual flowers almost completely flat across the top of the umbel.

The excessive fear surrounding the handling of common hogweed is unjustified: Urtica dioica (stinging nettles) cause a skin reaction unless handled with care, but still is tolerated everywhere. I have heard of fear reactions upon learning about the phytophototoxicity of the sap leading people to immediately rip all the common hogweed up. Fig trees and parsnips also contain furanocoumarins but we happily grow them. I advocate cautious handling of common hogweed, for example, either harvesting it on a cloudy day or to avoid getting the sap onto your skin by wearing gloves, using scissors or washing your hands shortly after handling. If sap does get on your skin it should be washed off immediately: as long as the sap on your skin doesn’t get exposed to sunlight you should not suffer a reaction. I teach foraging to school groups at Kamp Kernow, and one of the games I use to educate the children is edible or deadible. The idea is to instil the understanding that appearance is not enough to decide whether or not a plant is safe to eat: just because something looks edible, it does not necessarily follow that it is. ​

I explain to children about the sap in hogweed and how they must be careful to not get it on their hands (because it has a lovely hollow stem children are often tempted to use it as a pea shooter!). When I then ask whether they think it is edible or deadible, the answer is always deadible. But, as the reaction is triggered by sunlight, and as most of us know (unlike Donald Trump!) U.V. is unable to pass through our skin and enter our digestive system, hogweed is perfectly safe to eat! 

​A word of caution, hogweed is a member of the apiaceae family and to the amateur eye, the members of this family can resemble one another. The apiaceae family includes the most poisonous plants in the U.K., which are Conium maculatum and Oenanthe crocata (common hemlock and hemlock water-dropwort), so it is really important to ensure you get the right identification. Despite this, I think hogweed is one of the easiest apiaceae to identify, and if you want to focus on only one plant to forage I recommend hogweed because it is very delicious. I know children as young as 6 being able to accurately distinguish between hogweed and hemlock water-dropwort. The key is caution: fear gets in the way of learning, whilst caution keeps you safe.  ​

Close up of hogweed leaves to show the U-shaped groove that is a key ident feature.

Close up of the leaf of Oenanthe crocata (hemlock water-dropwort) to illustrate how hairless this plant is and the circular shape of the leaf stem lacking the groove.

Hogweed can become quite tall, up to 2 metres high. The stem is hollow and ridged, covered in fine hairs. The emerging leaves are curled up (the best time to pick for eating) and appear almost white from the hairs that cover them. The leaves slowly unfurl and can become pretty massive, in a deep green colour with the leaflets in a pinnate formation (either side of the central stem) divided into 3 or 5 lobes. The mature leaves have a serrated edge. The flower buds begin tucked up in a thin sheath that splits open to reveal the flowering heads. The flowering heads form white umbels (umbel is the Latin word for shade and the origin of the word umbrella) that always have a flattish top, like a hand holding a dinner plate aloft. ​

More hogweed flowering heads: they are so beautiful and almost always covered in insects of one kind or another!

Bit out of focus, but these are really pink flower buds!

​The flowers are in clusters of tiny white (or often pale pink) flowers consisting of 5 delicate petals. Once the flowers die back the seeds develop, green at first slowly becoming a pale brown colour, with a flattened oval shape and a distinct aromatic smell (I think they smell strongly of orange zest) when crushed. Luckily hogweed seeds are so distinctive you would be hard pressed to confuse them for common hemlock seeds.  ​

A beginner's hack which will help you distinguish between certain apiaceae but isn’t a blanket tool for identification is to look for a U-shaped leaf stem covered in fine hair. Hogweed, as well as wild carrot and cow parsley (Dacus carota and Anthriscus sylvestris) all have this distinctive feature. The highly poisonous apiaceae Conium maculatum and Oenanthe crocata (common hemlock and hemlock water-dropwort) both lack these features: they have smooth, hairless stems which are circular in shape. For those who are worried, giant hogweed also lacks the groove down the leaf stem, but does have very sharp, prickly spines (unlike the hairs on hogweed, which are soft and almost fluffy). This tool can help you to narrow down which apiaceae you have and aid to make an accurate id!

I couldn't resist including this photo, the flower heads are a joy to behold!

A good example of the sheath around an emerging flower head.

Hogweed dominating the edge of this pathway through the woods.