Tuesday, 7 April 2015
This unassuming little plant is just coming into flower at Filnore Woods.
It carpets the floor in places.
There are several explanations for the name Dog's Mercury. Apparently 'Dog's' is to show that it is not the true Mercury, another name for Good King Henry, a plant which used to be eaten as a vegetable. Dog's Mercury, however is poisonous. Don't try it !
Strangely, it is quite unusual to find female plants. The photo above shows male plants in flower. So It spreads by underground rhizomes or runners rather than by seed.
If you find it in a wood it is probable that the wood has been there for a long time. Our hedges, where the plant is mostly found at Filnore, are quite possibly the remnants of really ancient woodland.
Dog's Mercury thrives in the shade of woods and hedges and can spread on dry, alkaline soil at the rate of a metre per year. But it is out-competed by other plants in the open.