Biological and Cultural Control of Weeds and Nematodes
Dogs Mercury
1. Dogs Mercury (Mercurialis perennis)
One of the most common woodland plants, Dog’s Mercury can be found in most of Europe in
shaded copses but is almost absent from Ireland, and Northern Scotland. There are wide
extensive carpets of this plant on the floors of forests and beneath hedgerows. A member of the
Surge Family, It can be so dense that it even crowds out rarer species. Its appearance is most
prominent in May, though it can be found throughout spring.
Origins of its name.
The plant’s name originates from the legend that its medicinal virtues were discovered by the
Roman god, Mercury. This is also why it is known as Mercury’s Grass in Greece. In France, it is
referred to as La Mercuriale in France and in Italy, Mercorella. However, as the plant is
considered to be inedible, the term ‘dog’ was attached to it signifying its inferiority. In Greece
however it was used quite often for medicinal purposes. Mercury needed his health to deliver
the god’s messages thus the plant was attributed to him. The plant has many names such as
Adder's-meat, Boggard-flower, Bristol-weed, Dog's Cole, Kentish Balsam, Maiden Mercury,
Leaf Mercury, Sapwort, Snake's Bit, Snake Weed, and Town-weed.
Appearance
2. When full grown, its numerous hairy stems are very straight. Plants may reach a height of
about 15 in / 40 cm. Most leaves are on the top of the plant. The leaves are spear shaped and
reflect a lucid green. The leaves may be rough, smooth or hairy ovals. One of its most
characteristic features is the foul harsh smell it produces similar to rotting fish. It thrives in the
shade.
Growth and Habitat
Dog's Mercury grows abundantly in alkaline (basic) soils, particularly that which is rich in
humus. Armies of them can be found suitable habitats in limestone regions. They can also
survive neutral soils. However they cannot grow in acidic ones. Usually one can find it in the
broad-leaved forests and groves. It grows very fast. Dog's mercury is an aggressive plant that
is self-sustaining and can grow by itself. Male and female versions of Dog’s Mercury plants
usually grow in separate bunches, the females being less common.
Chemical Characteristics
Dog's mercury is highly poisonous when eaten! It contains methylamine, trimethylamine,
saponins and a volatile oil. It can lead to vomiting, pain, gastric and kidney inflammation.
Larger doses can cause lethargy, jaundice, painful urination, apparently by making the urine
acid and coma before death.
The first known account of this happened in 1693, when a family became seriously ill as a result
of eating the plant (after boiling and frying it); one of the children died some days later.
In the 1980s, a couple was reported to have eaten the leaves, boiled, and thinking it to be a
green vegetable. Luckily they recovered in two days.
Dog's Mercury was even once eaten in mistake for Good King Henry, when boiled and eaten
with fried bacon in error for this English spinach; it produced sickness, drowsiness and
twitching. In another instance, when it was collected and boiled in soup by some vagrants, all
partaking of it exhibited the ordinary symptoms of narcotic and irritant poisoning, two children
dying on the following day.
3. Sheep and Cattle have even eaten it in mistake. It is poisonous in the fresh state. It has been
said, however, that heat destroys its harmfulness. Its chemical constituents have not been
ascertained.
Uses
The famous doctor and botanist, Dioscorides, has demonstrated that a tincture of male
flowers of Dog’s Mercury increased the possibilities of having a male child, and
similarly female flowers increased the likelihood of a girl
It is can be used as a natural cosmetic
A lotion is made from the plant.
The seeds are quite large (about 3 – 4 mm in diameter) and ‘offer a meal’ to small
mammals and birds.
Its main use is as a laxative however its medicinal use is discouraged by herbalists
It was used in treating warts, sores, inflammation, watering eyes, deafness, rheumatism,
dropsy, diarrhea and disorders of the gall bladder and liver however it is now not
recommended in medicinal use by herbalists.
When steeped in water, the leaves and stems of the plant give out a fine blue color,
resembling indigo. This can be used to make a dye.
References
http://chestofbooks.com/flora-plants/flowers/British-Wild-Flowers-1/Dog-s-Mercury-Mercurialis-
Perennis-L.html#.U1owVeNdV34
http://practicalplants.org/wiki/Mercurialis_perennis
http://www.herbs2000.com/herbs/herbs_dogs_mercury.htm
https://www.botanical.com/botanical/mgmh/m/merdog31.html
http://www.woodlands.co.uk/blog/flora-and-fauna/dogs-mercury/
http://www.thepoisongarden.co.uk/atoz/mercurialis_perennis.htm
