White Bryony, Bryonia dioica, is Britain’s only native member of the cucumber family, the Cucurbitaceae. Like Black Bryony, Tamus communis, which I wrote about a couple of years ago, it is a climbing perennial plant that adorns English hedgerows (see map). But Black Bryony is not a close relative – it is Britain’s only member of the mainly tropical Yam family, the Dioscoreaceae.

As the specific name dioica suggests, White Bryony is a dioecious plant – the male and female flowers with their five greenish-white petals occur on separate plants. Male flowers are 12 to18mm across, with green veins, two pairs of stamens with united filaments and a third stamen is on its own. The anthers are yellow. Female flowers are 10 to12mm across, with three forked stigmas.

My photograph (taken near Hoveton in Norfolk) shows the plant in mid July, with the green berries ripening through orange to a dull red. In winter the plant dies back but the old stems remain for a while with the berries attached. In spring the shoots rapidly climb and attach themselves to supports with coiled tendrils. The leaves are palmate with three to five lobes.

The closely related Bryonia alba grows in mainland Europe and Iran but not in Britain. It is monecious, with separate male and female flowers on the same plant. It is equally poisonous and has also been introduced into the United States, where it is a noxious weed in Washington, Idaho and Montana. The related Bryonia cretica subsp. dioica is an invasive species in New Zealand.

Like Black Bryony, White Bryony is a poisonous plant. Eating a few of the berries can result in vomiting, diarrhoea (with blood), dizziness and breathing difficulties.The roots are very poisonous to cattle and horses. Eating parts of the plant has been known to kill ducklings and poultry as well. Not much is known about the toxins in White Bryony, though they include a glycoside called bryonin and an alkaloid, bryonicine (Marion R. Cooper & Anthony W. Johnson, “Poisonous Plants & Fungi – An illustrated guide”, HMSO, 1988).  Tetracyclic terpenes (cucurbitacins) may also be involved.

The website A Modern Herbal lists the medicinal properties of White Bryony, as well as several alternative names for the plant, including English Mandrake, Wild Vine, Wild Nep, Ladies’ Seal and Tetterbury. French name for White Bryony include Navet du diable (Devil’s Turnip) and Rave de serpent (Snake Root).

The American WebMD website warns that:

“Bryonia is UNSAFE for anyone to use. At fairly low doses, it can cause many side effects including dizziness, vomiting, convulsions, colic, bloody diarrhea, abortion, nervous excitement, and kidney damage. Larger doses may cause fatal poisoning in adults and children. Just touching fresh bryonia can cause skin irritation. Eating the berries can cause death.”

The whole plant has an unpleasant and acrid smell when cut and the berries are apparently bitter, which must have prevented some potential Bryony tasters.

Historically, White Bryony roots were sometimes used as a cheap substitute for the Mediterranean plant Mandrake (Mandragora officinarum). Mandrake roots often grow to resemble the human form and were therefore considered (under the Doctrine of Signatures) to be useful for enhancing sexual potency. But as Mandrake doesn’t grow in Britain’s cooler climate, it was cheaper and more convenient to carve White Bryony roots to look like like Mandrake roots or even to grow them in special moulds to form the expected shape.

“Jugglers and fortune-tellers make wonderful monsters of this root, which, they have hid in sand for some days, they dig up for Mandrakes; and by this imposture these knaves impose on our common people.” – John Pechey.

The above quote by John Pechey comes from Robert Bevan-Jones’ excellent book, “Poisonous Plants: A Cultural and Social History”, Windgather Press 2009.

You can read more about Mandrake and White Bryony on The Poison Garden website here (July 2011) and here (February 2012).

King’s American Dispensatory gives some interesting information on the uses of Bryonia species, originally printed in 1898 but now online as part of the Henriette’s Herbal Homepage website.