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.’

Rook

 

An unexpected visitor to the garden bird feeder this week: a rook. They don’t appear in the garden very often, but when they do it’s usually in early spring, when they are looking for twigs to renovate nests.

Ffty years ago, when we first came to live in this small market town in the foothills of the North Pennines, on the edge of farmland, we used to have two large rookeries close-by, but as the town has grown, with new housing around its margins, they’ve shifted their nests further away. It’s a long-term pattern of behaviour that has been well documented in many places: rooks generally do not tolerate a lot of disturbance under their rookeries.

 Peering up into a rookery on a windy spring day, at the swaying nests overhead, can be disorientating, unless you steady yourself by leaning against a tree trunk, feeling the transmitted power of the wind when the bole flexes against your back. Down below, earthbound, there is something Hitchcockian about those dark silhouettes wheeling overhead, with their broad wings, finger-like primaries and bony dagger beaks that prise insect grubs from grassroots.

The rooks ride the gusts, sometimes settling into what sounds like conversational cawing, often rising as a raucous flock for no obvious reason. A few bring twigs to repair nests, others seem to be here just to be sociable.

It seems strange to see these ungainly birds visiting the garden bird table because their pickaxe beaks seem ill-adapted for picking up sunflower and millet seeds, but they are birds with a very varied diet.

Come summer, after the harvest, when the breeding season is over, they’ll be pacing through local stubble fields, in the company jackdaws and crows, looking for wheat, barley and oat seed that the combine harvester dropped: nature’s gleaners at work.

A bit of a stink

 

 Stinking hellebore Helleborus foetidus, malodorous but a wonderful source of pollen and nectar for the first bees to emerge in spring, started flowering in the garden last week. Its nectar is secreted into nectaries formed from small tubular petals inside those green sepals, and only accessible to long-tongued bumblebees that must hang under the bell-shaped flower to reach it. The specialised nectaries are more easily visible on open-flowered hellebores like ….

…… this non-native Helleborus argutifolius, also flowering now. The petal/nectaries are the ring of dark green structures tucked in behind the stamens.

Hellebores, which are poisonous, have a somewhat gruesome history in folk medicine, as a vermifuge: “Where it killed not the patient, it would certainly kill the worms; but the worst of it is, it would sometimes kill both” noted Gilbert White in 1779, in The Natural History of Selborne.