Dog's Mercury - Mercurialis perennis Dog's Mercury - Mercurialis perennis

Herb: Dog's Mercury

Latin name: Mercurialis perennis

Family: Euphorbiaceae (Spurge Family)

Medicinal use of Dog's Mercury:

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.

Description of the plant:


30 cm
(11 3/4 inch)

to April


Habitat of the herb:

Woods and shady places, usually in beech and oak woods, avoiding acid soils.

Other uses of Dog's Mercury:

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.

Propagation of the herb:

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.

Cultivation of Dog's Mercury:

Woods and shady places, usually in beech and oak woods, avoiding acid soils.

Known hazards of Mercurialis perennis:

All parts of the plant are poisonous.

Plant information taken from the Plants For A Future.