Dog's Mercury
Mercurialis perennis
Summary
Dog’s Mercury can be seen carpenting woodland floors and appears in the same places Wild Garlic is often found. Whilst quite distinctive, it is very easy to get some of this plant mixed in when grabbing handfuls of Wild Garlic with gay abandon. So be careful!
Edibililty & Uses
Extremely poisonous. Ingestion can cause vomiting, jaundice, coma, and potentially death.
Parts Used
No parts of this poisonous plant can be used. It is poisonous to humans and other mammals.
When to forage?
Dog’s Mercury is a very common plant and one every beginner should be aware of. It has a penchant for the same habitats as wild garlic and for this reason must be considered when gathering Wild Garlic.
Where to forage?
Common throughout Britain except in northern Scotland. It is much less frequent in Ireland.
Similar Species
How to tell Wild Garlic from Lords and Ladies and Dog’s Mercury
Wild Garlic (Allium ursinum) is an excellent beginner wild edible for many reasons. It’s common, versatile, tasty, easy to identify and has just the right balance of potential pitfalls to begin developing your awareness of other plant species as you forage.
There are only two species that you really need to be mindful of when harvesting wild garlic; Lords-and-Ladies (Arum maculatum) and Dog’s Mercury (Mercurialis perennis). They both grow within the same habitats and appear at the same time as Wild Garlic, and they are both considered poisonous. Lords-and-Ladies will give you some incredibly painful experiences – like eating a bag of broken glass, and Dog’s Mercury can cause some extremely unpleasant symptoms and even death.
Right – Young Lords-and-Ladies leaves in different development stages
Lords-and-Ladies bear a slight similarity with its blade-like young leaves, however the differences soon become very apparent once the plant has developed. The leaves are broader with backwards pointed lobes and usually develop spots. Wild Garlic leaves remain long and pointed at the tip. Note the deeper veins radiating from the centre on the Lords-and-Ladies leaves, compared to the much less pronounced vertical lines running from base to tip of Wild Garlic.
Dog’s Mercury looks nothing like Wild Garlic, but the reason it’s mentioned is that it commonly grows amongst it. I have seen on more than one occasion enthusiastic beginners grabbing handfuls of Wild Garlic to put in their basket, unaware that they have also picked some Dog’s Mercury or Lords-and-Ladies. And this is the only real danger. It’s very easy to forget that vital first step of 100% positive identification of everything you add to your foraging basket in the face of an apparently obvious patch of abundant wild food.
Fortunately, Wild Garlic has a very obvious ID characteristic – the plant smells strongly of garlic.
The key take-away here is that no matter your experience level, complacency can leave you in a pickle, so stay mindful as you fill your baskets.