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Annual Mercury

Mercurialis annua

Please keep in mind that it is illegal to uproot a plant without the landowner's consent and care should be taken at all times not to damage wild plants. Wild plants should never be picked for pleasure and some plants are protected by law.
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Plant Profile

Flowering Months:
Euphorbiaceae (Spurge)
Life Cycle:
Maximum Size:
1 metre tall
Fields, gardens, hedgerows, riversides, roadsides, towns, walls, wasteland, waterside, woodland.

Green, no petals
Green catkins. Pollinated by the wind, bees and flies.
The fruits are dry and bristly.
An annual flower with broadly oval to lance-shaped, pale green leaves. The leaves are in opposite pairs along the stems. The stem is erect. The leaves of Annual Mercury are paler than those of the similar looking Dog's Mercury (Mercurialis perennis).
Other Names:
Dog's Mercury.
Frequency (UK):
Occasionally seen  

Similar Species

Other Information


Mercurialis annua, also known as annual mercury or dog's mercury, is a species of herbaceous perennial plant in the Euphorbiaceae family. It is native to Europe, Asia, and North Africa. The plant typically grows to a height of 100cm and produces small, greenish-yellow flowers in the spring. The leaves are glossy green and typically appear after the flowers. The plant prefers shady, moist locations and is often found in woodlands, hedgerows, and along streams. Mercurialis annua is considered a weed in many areas, and it is toxic to livestock if consumed in large quantities. Its toxic properties make it of no use in medicine or agriculture.


Annual Mercury, also known as Mercurialis annua, is a common plant found in many regions of the world, including Europe, Asia, and North Africa. It belongs to the Euphorbiaceae family and is an annual herbaceous plant that can grow up to one meter in height. The plant is easily recognizable due to its unique appearance, with small greenish-yellow flowers and oval-shaped leaves.

Annual Mercury has been used for centuries for medicinal purposes, particularly in traditional Chinese medicine. It was believed to have diuretic properties and was used to treat conditions such as edema, urinary tract infections, and kidney stones. In European traditional medicine, the plant was used to treat skin diseases, particularly eczema.

The leaves and stems of Annual Mercury contain a variety of chemical compounds, including flavonoids, phenolic acids, and alkaloids. These compounds are believed to be responsible for the plant's medicinal properties. In recent years, research has been conducted to investigate the potential health benefits of Annual Mercury.

One study found that an extract of Annual Mercury exhibited anti-inflammatory properties, which could make it useful in the treatment of inflammatory conditions such as rheumatoid arthritis. Another study found that the plant has antimicrobial activity against a range of bacteria, including Escherichia coli and Staphylococcus aureus. This could make it useful in the treatment of bacterial infections.

Despite its potential health benefits, Annual Mercury should be used with caution. The plant is toxic and can cause adverse effects if consumed in large quantities. Ingesting the plant can cause nausea, vomiting, diarrhea, and abdominal pain. It is not recommended for pregnant or breastfeeding women, as it may cause harm to the developing fetus or infant.

Annual Mercury has also been used in folk medicine to treat a variety of ailments, including jaundice, menstrual problems, and as a laxative. It has also been used topically to treat skin conditions such as eczema, psoriasis, and ringworm.

The plant is typically found in fields, meadows, and along roadsides, and it thrives in moist soil conditions. It is an annual plant, which means it completes its life cycle within one year. The plant flowers from April to June and produces small greenish-yellow flowers that are unisex.

Apart from its medicinal properties, Annual Mercury has also been used for other purposes. In traditional agriculture, the plant was used as a green manure crop to improve soil fertility. The plant was plowed under before it could produce seeds, which would have otherwise become a weed problem. In addition, Annual Mercury has been used to make a green dye that was used to color wool and other fabrics.

Annual Mercury has also been studied for its potential use in cancer treatment. Some studies have shown that the plant contains compounds that have anti-cancer properties, and may be useful in the treatment of certain types of cancer. However, more research is needed in this area to determine its safety and effectiveness.

Another potential use for Annual Mercury is in the production of biofuels. The plant contains high levels of oil, which can be extracted and used to make biodiesel. This could be a sustainable alternative to fossil fuels and could help to reduce carbon emissions.

In some countries, Annual Mercury is considered a weed and is considered a nuisance plant. This is due to its ability to spread quickly and its toxic properties. It can also cause allergies in some people, particularly those with sensitive skin. As a result, it is important to be cautious when handling the plant, and to wear gloves and protective clothing.

Annual Mercury is a plant with a long history of use in traditional medicine. While it has potential health benefits, caution should be exercised when using it, as it is toxic and can cause adverse effects. Further research is needed to determine its effectiveness and safety for various uses, including in cancer treatment and as a biofuel source. Ultimately, Annual Mercury is a fascinating plant with a range of potential uses, and more research will undoubtedly uncover further benefits in the future.

In some parts of the world, Annual Mercury is also used as an ornamental plant. Its unique appearance and ability to thrive in a variety of soil conditions make it a popular choice for gardeners. It is also attractive to pollinators, such as bees and butterflies, making it a valuable addition to any garden.

Annual Mercury is relatively easy to grow and can be propagated from seed. It prefers moist soil conditions but can tolerate drought and heat. It is a fast-growing plant that can reach maturity within a few months.

In some cultures, Annual Mercury has also been used in religious ceremonies and rituals. In ancient Greek mythology, the god Mercury was associated with healing and the plant was named after him due to its healing properties. In addition, the plant has been used in traditional Chinese medicine as a spiritual tonic to help calm the mind and enhance spiritual awareness.

Overall, Annual Mercury is a fascinating plant with a long history of use in various cultures. While its medicinal properties are of particular interest, its versatility and potential uses in other areas such as biofuels and ornamental gardening make it a plant of great interest to scientists and gardeners alike. With ongoing research, we may uncover further benefits and potential uses for this remarkable plant in the years to come.


2 Annual Mercury videos, both filmed at Orford, Suffolk on the 29th June 2022.

Video 1:


Video 2:

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