Green dog’s mercury
By Sarah Das Gupta
your tiny secret flowers
toxic to canines
Originally a coloniser of ancient woodland, dog’s mercury is a useful ancient woodland indicator, determining areas of ancient woodland, even if there is no tree cover. Some ground-nesting birds like woodcock seem drawn to the plant. Speckled bush cricket nymphs feed on it, as do species of beetle, weevil and mollusc. It is a contributor to biodiversity in ancient woodland.
All parts of this plant are poisonous and can induce jaundice, diarrhoea, vomiting, even death. The epithet ‘dog’ in this context means ’lesser’ or ‘inferior’ to other plants of the family, as applied to other species such as ‘dog’ violet or ‘dog’ rose. The reference to ‘mercury’ probably refers to the god Mercury and the medicinal properties of the species.
From ancient times it has been used externally and its juice is emetic, ophthalmic and purgative. It was used particularly to treat warts and sores. If the leaves are thoroughly heated and dried, it is no longer toxic.
| Botanical name: | Mercurialis perennis |
| Popular names: | Dog’s mercury, false mercury, boggard posy, dog’s cole |
| Family: | Euphorbiaceae |
| Origin: | Native to most of Europe – almost excluding Ireland, Orkney and Shetland |
| Flowering: | February to April |
| Habitat: | Ancient woodland, broad-leaf woodland, hedgerows |
Further reading:
‘Collins Complete Guide to Wild Flowers’, Paul Sterry, 2006, HarperCollins Publishers.
‘Meadowland: The Private Life of an English Field’, John Lewis-Stempel, 2014, Transworld Publishers Ltd.
Articles from ‘The Woodland Trust‘ and ‘Nature’.
Author bio:
Sarah Das Gupta is a young 81 year old. Loves writing haiku and most forms of poetry. Is learning to walk after an accident. Main outside interests include equine sports. Lives near Cambridge, UK. Read other sciku by Sarah here: ‘Redundant Ergot‘, ‘Redundant Vets’, ‘Bird’s Foot Trefoil’, ‘Mistletoe’ and ‘The Glastonbury Thorn’.