Cow parsley/giant hogweed
IN his seminal book The Englishman’s Flora published in 1958, the British poet, writer, and naturalist Geoffrey Grigson refers to cow parsley, Anthriscus sylvestris as a “plant of lace and moonlight” and also comments on it as “whitening the road verges” in June, although these days it tends to come into flower earlier, in May.
It is also known as wild chervil, wild beaked parsley and kec. Environmentalist Richard Mabey states in his book, Flora Britannica 1996 that “Cow parsley is arguably the most important spring landscape flower”. In May its flowers are as ubiquitous as hawthorn blossom and is attractive to a huge number of creatures, from orange-tip butterflies to marmalade hoverflies, and even rabbits. It is part of the Apiaceae family, more commonly known as umbellifers. Apiaceae is a large family consisting of the celery, carrot and parsley variants of which there are over 3,000 species.
Cow parsley is a hollowstemmed, tall plant that grows rapidly in summer before dying back. It likes shady habitats, and can be found decorating woodland edges, roadside verges and hedgerows with masses of frothy, white flowers and grows to a height of 60–170cm. These flower umbels (umbrella-like clusters) appear from May until June. Cow parsley has large, flat umbrellas of small, white flowers, and large, fern-like leaves. 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 is the earliest flowering of the umbellifers. Other similar looking plants are fool’s parsley, Aethusa cynapium, the smaller and later flowering upright hedge-parsley, Torilis japonica, wild carrot, Daucus carota and the poisonous hemlock, Conium maculatum. Hemlock’s leaves are like those of cow parsley but is much bigger with its stem is spotted with purple markings and grows to around two metres.
Another related species, giant cow parsley, better known as giant hogweed, Heracleum mantegazzianum is an immensely tall umbellifer that displays large, white, umbrella-like clusters of flowers. Its hollow stem is ridged and purple-spotted, and its leaves are large and divided. It was introduced into the UK by the Victorians from the Caucasus Mountains (located at the intersection of Europe and Asia) as an ornamental plant for lakesides and gardens. It escaped into the wider countryside and gained notoriety in the 1970s as an alien species that favours damp spots like riverbanks. At this time, many children started to display blisters as a result of touching the plant’s sap while using the stems to make pea-shooters or telescopes; sunlight makes the skin sensitive to the irritants in the plant, causing the skin to redden.
Control is a challenge and should be left to experts and hand-cutting should never be undertaken unless the operator is wearing full protective clothing to prevent skin contamination by the sap. Infestations need to be controlled by digging out the whole plant as cutting through the stem must be done below ground level to ensure damage to the rootstock and to prevent regrowth from the base. Its favoured position by the banks of rivers allows giant hogweed the perfect opportunity to expand as it sends its seeds into the water to be dispersed by its flow. Each plant can produce 30-50,000 seeds each year and colonies can quickly overtake a habitat, crowding out native plants.
Legislation has been applied to invasive alien species, including giant hogweed. In line with The Wildlife and Countryside Act 1981 (as amended) it is an offence to cause giant hogweed to grow in the wild in England and Wales (similar legislation applies in Scotland and Northern Ireland). Also, it can be the subject of Antisocial Behaviour Orders where occupiers of giant hogweed infested ground can be required to remove the weed or face penalties.