03-Aug Poison & Parsley: The Dangerous Allure of August Umbellifers

The common spring species such as cow parsley, hemlock, rough chervil and ground elder are all now coming to an end. They are being replaced by Upright hedge parsley Torilis japonica along paths, Hogweed Heracleum sphondylium in hedgerows, Fool’s watercress Apium nodiflorum beside rivers and Burnet saxifrage Pimpenella saxifraga as well as Stone parsley Sison amomum in chalky areas. Rather rarer are Lesser water parsnip Berula erecta and the Hare’s ears Bupleurum spp. The latter plants are so attractive that they are worth looking out for in gardens e.g. Shrubby Hare’s ear Bupleurum fruticosum.

False Thorow-wax B. lancifolium is a rarity occasionally found on refuse tips. Slender Hare’s ear B. tenuissimum is occasionally seen on sea walls along the lower Thames and for a chance of seeing Sickle-leaved Hare’s ear B. falcatum you may have to visit Reigate Heath.

Umbellifers that are eaten, such as parsley, cumin, caraway, dill and coriander all occasionally seed themselves in and out of gardens. Wild celery and wild fennel do the same along the banks of the tidal Thames. Wild Angelica Angelica sylvestris is also now in flower.

This is a tall, handsome plant whose umbels look as if they have been dipped in claret. It also can be found along river banks but looks its best when encountered in wet woods. This wild plant is not to be confused with Garden Angelica A. archangelica which could have been found earlier in the year naturalised along the river Lea. This is the species whose stems are candied before they are eaten. In the past this was a big industry, especially in Prussia, with even William Turner, the sixteenth century Father of British botany, mentioning his excitement about his candied angelica arriving from Danske.

Most care has to be taken identifying the poisonous umbellifers, particularly the dropworts Oenanthe spp. Because the sweet, yellow roots of Hemlock water dropwort Oenanthe crocata look so much like parsnips they have been responsible for more deaths than any other British plant. On some occasions, death has been so rapid no prior symptoms were noticed.

Other dropworts such as Tubular Water dropwort O. fistulosa, River Water dropwort O. fluviatilis and Parsley Water dropwort O. lachenali are all also poisonous but not quiet so lethal. Fortunately, all these species are not common with the last example disappearing as I write. Another poisonous species to look out for this month is Fool’s parsley Aethusa cynapium which can cause nausea, vomiting and tremors. This is a common weed at the sides of fields and along the banks of the Thames estuary.

Far more dangerous in the past was Cowbane Cicuta virosa which, when it was more common, was responsible for many cattle poisonings, half of such cases resulting in fatalities. Its symptoms included giddiness, excess salivation, fits, leading on to death by suffocation. The last symptom is common in a number of other poisonous umbellifers.

Then there are the species which can cause the skin to blister. The best known example of this is Giant Hogweed Heracleum mantegazzianum. Less well-known is that even celery, angelica and carrot can cause similar skin allergies in sensitive individuals.

Wild parsnip Pastinaca sativa is the worst, causing severe blistering if handled on a sunny day. Fortunately, although common, this plant tends to be confined to chalky districts and has distinct lime yellow flowers which help to identify it.

Other umbellifer species of note include Bullwort Ammi majus and the handsome Longleaf Falcaria vulgaris both of which occasionally make rare appearances. Lastly, Field Eryngo Eryngium campestre has been described as London’s most precious flower, having only been found once in the grounds of a hospital in Dartford, and this was in the 1960s.