Dog's mercury and the perils of colloquial plant names

 

Everyone looks forward to finding the first primroses, violets and bluebells blooming in spring, but the flowering of dog’s mercury Mercurialis perennis never gets a round of applause. But what it lacks in beauty, it makes up for with ecological gravitas and toxicity.

Dog’s mercury is common in woodlands almost everywhere and spreads via an underground rhizome, so large patches tend to be good indicators of very old woodlands and hedgerows. There are separate male and female plants, with the former being rather more common. This is a male plant, with stamens protruding from the tiny flowers.

Old colloquial plant names, like mercury, can lead to potentially dangerous confusion. The pot herb Good King Henry Chenopodium bonus-henricus also goes by the old name of English mercury and it is edible but dog’s mercury is most definitely poisonous. John Gerard, referring to it as French mercury in his herbal of 1597, seems to have confused the two, which may be why he wrote that it ‘cleanse and scour away the excrements and other filth contained in the guts. It serveth to purge the belly, being eaten or otherwise taken, voiding out of the belly not only the excrements, but also phlegm and choler.’

..... more Spring Greens

Someone asked me a while ago why most spring wild flowers are yellow. Having thought about it for a bit, I'm not sure that's really the case ....... thanks to their sheer numbers, yellow-flowered lesser celandines and primroses are a very conspicuous part of the flora, but there are quite a few green-flowered spring species too. Perhaps the most interesting is Moschatel Adoxa moschatellina, also known as town-hall clock on account of the fact that four of its tiny flowers face outwards, like clock faces on a clock tower. There's also a fifth flower in the inflorescence, that points directly upwards, and one of the unusual features is that the single upward-pointing flower has four petals whereas the four outward-facing flowers have five.

Moschatel is an inconspicuous plant but it's worth taking a close look at the flower with a magnifying glass ..... and taking a sniff. It has a faint musky smell after rain, which is said to attract small flies...although my sense of smell isn't what it once was, and I can barely detect it.

There's nothing faint about the smell of Alexanders Smyrnium olusatrum flowers ...... it's just downright unpleasant and attracts flies. This glossy-leaved umbellifer was once cultivated as a pot-herb and it's quite common around the coast - often near habitation, suggesting a garden origin. Large numbers of plants are coming into bloom on the headland at Tynemouth now, but .....

.. there's a distinct shortage of flies around to pollinate its flowers, although this black ant was attracted by the nectar.

Forty years ago, when I lived in Sussex I used to find spurge laurel Daphne laureola quite frequently in beech woods but up here in Durham it's much less common. There are some plants in Castle Eden Dene and a few in Weardale. Its sweet-scented green flowers attract the first bumblebees to emerge from hibernation and it produces black berries in summer.

Dog's mercury Mercurialis perennis is common everwhere. It spreads via a slow-growing underground rhizome, so large patches tend to be good indicators of old woodlands and hedgerows. There are separate male and female plants, with the former being rather more common.

Like most flowers, even those of dog's mercury become more interesting when you take a close look .... these are the flowers of a male plant, with the anthers shedding pollen, which is carried by the wind rather than by insects.