Dog's Mercury
Mercurialis perennis
Family: Euphorbiaceae
What it is like
Mercurialis perennis is a PERENNIAL growing to 0.3 m (1ft) by 1 m (3ft 3in) at a fast rate. See above for USDA hardiness. It is hardy to UK zone 4 and is not frost tender. It is in flower from February to April, and the seeds ripen from May to June. The species is dioecious (individual flowers are either male or female, but only one sex is to be found on any one plant so both male and female plants must be grown if seed is required). and is pollinated by Wind, flies. The plant is not self-fertile. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in full shade (deep woodland) or semi-shade (light woodland). It prefers moist soil.
Height (m): 0.3
Where it is found
Woods and shady places, usually in beech and oak woods, avoiding acid soils.
Europe, including Britain, from Scandanavia south and east to Spain and S.W. Asia.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 0
Oil: Oil
Medicine
Rating: 1
Dog's mercury is poisonous in the fresh state, though thorough drying or heating is said to destroy the poisonous principle. The fresh juice of the whole plant is emetic, ophthalmic and purgative. It is used externally to treat women's complaints, ear and eye problems, warts and sores. A lotion made from the plant is used for antiseptic external dressings. A homeopathic remedy is made from the plant. It is used in the treatment of rheumatism, dropsy, diarrhoea and disorders of the gall bladder and liver.
Emetic: Induces vomiting.
Homeopathy: A plant used in homeopathic treatments.
Ophthalmic: Treats eye complaints.
Purgative: A drastic laxative causing a cleansing or watery evacuation of the bowels, usually with a griping pain.
Warts: Used in the treatment of warts, corns etc.
Women's complaints: A very vague title, it deals with a miscellany of problems peculiar to the female sex.
Other
Rating: 2
A fine blue dye is obtained from the leaves, it is turned red by acids and destroyed by alkalis but is otherwise permanent. It resembles indigo. A yellow dye is obtained from the leaves. The seed is a potential source of a very good drying oil.
Dye: Plants that provide dyes.
Oil: Vegetable oils have many uses, as lubricants, lighting, soap and paint making, waterproofing etc. This does not include the edible oils unless they are also mentioned as having other uses.
Scented Plants: Plants noted for their scent
How it is grown
Prefers a humus rich soil. Dog's mercury is a very invasive and common hedgerow plant, it should not be necessary to cultivate it. Male and female plants usually grow in separate clumps, the females being less common. The leaves contain trimethylamine and, in the early stages of putrefaction or when bruised, they give off the smell of rotting fish. Dioecious. Male and female plants must be grown if seed is required.
Propagating it: Seed - the plant shouldn't need any help in spreading itself, but if you are desperate to be completely overrun by it then you could spread the seed around when it is ripe in late spring and early summer. Division - once again, there really is no need to help the plant but you can divide the roots at any time of the year.
Best place to grow: Woodland Garden not Deep Shade;
Habit: Perennial
Hardiness: 4-8
Growth: Fast
Soil: Light (sandy), medium, heavy (clay)
Shade: Full shade, semi-shade
Moisture: Moist
Things to keep in mind
All parts of the plant are poisonous.