Black Bryony

Overview

Black bryony is the only British member of the yam family, a tropical lineage that reaches its northern limit in the hedgerows of England and Wales. It climbs without tendrils, twining its stems clockwise around whatever support it finds — hawthorn, elder, bramble — and in winter its presence is made known by cascades of berries running from green through orange to vivid scarlet-red, strung along bare stems like a garland. They are among the most striking sights of the winter hedge, and entirely poisonous. The tuber, large and swollen beneath the ground, contains calcium oxalate crystals and saponins in concentrations that make it acutely toxic. The berries are particularly dangerous to children. This is a plant whose beauty and habitat make casual contact likely — and whose toxicity is correspondingly underappreciated.

Botanical Notes

A climbing perennial with a large, black-skinned, mucilaginous tuber. Stems twine clockwise, reaching 2–4 metres. Leaves heart-shaped, glossy, pointed, with a palmate vein pattern. Flowers small, yellowish-green, dioecious — male and female on separate plants; male flowers in long racemes, female in shorter clusters. Berries 1–1.5cm, ovoid, turning from green through yellow and orange to brilliant red on maturity, persisting well into winter. Found in hedgerows, scrub, and woodland margins throughout England, Wales, and southern Ireland; absent from Scotland. Closely related to tropical yam species but not edible. Not to be confused with white bryony (Bryonia dioica), which is also toxic but belongs to the gourd family.

Lore & History

The name bryony is from the Greek bryein, to grow luxuriantly — applied to both black and white bryony on account of their vigorous climbing habit. Black bryony root was known in old herbalism as the 'wild nep' or 'lady's seal,' and the large tuber was sometimes sliced and applied as a rubefacient poultice to bruises and chilblains, the irritant oxalate crystals producing counter-irritant warmth. Culpeper assigned it to Mars — a plant of heat and aggression, suitable for drawing out cold stagnation. This external use was the plant's only practical role in folk medicine; its internal toxicity was well understood. In the winter hedge, the red berry chains were sometimes gathered for decoration, bringing the plant's brightness indoors — and occasionally, its danger.

Warnings