Dog's Mercury

Scientific Name: 
Mercurialis perennis

A common plant often seen carpeting the floor of ancient woodlands, Dog's Mercury can quickly colonise and spread by its underground rhizomes (stems). It can be so expansive that it shades woodland floors and crowds out rarer species like Fly orchids and Oxlip. It produces small flowers from February to April, but leaves can persist throughout the year.

How to identify: 
Dog's Mercury has spear-shaped, toothed, fresh green leaves carried on upright stems. It produces a foul and rotten smell and bears clusters of small, greenish flowers in spring.
Where to find it: 
Widespread throughout mainland UK.
How people can help: 

The Wildlife Trusts manage many woodland nature reserves sympathetically for a range of wildflowers. A mix of coppicing, scrub-cutting and ride maintenance open up the woodland floor to the sun, helping many flowers and plants to thrive and keeping others that spread easily, such as Dog's Mercury, under control. You can help too: volunteer for your local Wildlife Trust and you could be involved in everything from traditional forest crafts to raising awareness about woodland wildlife.

Statistics: 
Height: up to 35cm
Conservation status: 
Common.
Did you know?: 
Unlike the 'true' mercuries (Chenopodium species such as Good-King-Henry), Dog's Mercury is highly poisonous and hence became 'false' or 'dog's' mercury. Ingestion of this plant can lead to vomiting, jaundice, coma and eventually death.
Seasons: 
Spring
Summer
Autumn
Winter
When to see
Start date: 
January
End date: 
December
Image: 
Dog's mercury - Philip Precey