Western Morning News (Saturday)
Carnivorous plant lurking in the mires
Insects beware, all is not as it seems when bog plants offer sweet treats, as Charlie Elder discovered when he went in search of the peculiar sundew plant
We don’t have Venus flytraps growing wild in Britain – those small triffid-like plants from North America which snap shut their fanged jaws around unfortunate flies.
A source of fascination, given their rapid reactions which challenge our thinking of plants as wholly inactive organisms, they are sometimes seen for sale alongside cacti in shops which specialise in the weird and wonderful.
However, we do have a similarly carnivorous group of wetland plants which grow in boggy places around Britain, and this week I went in search of one of them.
Fortunately, I live next to one of the boggiest places around – Dartmoor – so there is no shortage of places to look.
On a sunny day this week I donned my walking boots and set off for two sites on west Dartmoor where streams seeping from hillsides and rainwater run-off create muddy gullies and soggy expanses in which bog plants thrive.
The first site I visited is an area I know well, a place where thin runnels winding down a gentle slope slow and soak into the surrounding ground, ensuring it remains wet throughout the year.
This mire is far from easy to cross, requiring one to step on tussocks of sedge and grass to avoid submerging a boot in the oozing mud or pockets of water hidden beneath floating vegetation.
But the location, amid the streams and the marshy ditches where peat was once cut, is a haven for moisture-loving plants.
The wonderfully-named devil’s-bit scabious is still in flower, while the yellow heads of bog asphodel have now faded to orangey-brown, and there is the odd fluffy tuft of cotton-grass amid the vivid green cushions of sphagnum moss.
This water-logged acidic habitat is
poor in nutrients, and a place where specialist species able to source the minerals and molecules they require can get a foothold.
Among them is the sundew, which adopts dastardly methods to obtain vital nutrients.
It can be difficult to spot, until you gets your eye in. When standing up, this low little plant growing at ground-level is easy to miss. It appears like a palm-print of red a few centimetres across, amid the mossy greens and peaty browns.
Kneeling down to inspect more closely, one observes a delicate rosette of scarlet stems radiating from the centre, each topped with a circular fleshy green leaf, smaller than a one pence piece and fringed with reddish hairs the tips of which bear sticky, sugary globules. The hairs remind me of the bristles on some hairbrushes which are tipped with plastic droplets.
These leaves with their sweet sticky halos are designed to ensnare any insects that make the mistake of landing on them. Responding to touch, the leaf gradually folds inwards once the prey is secured, before enzymes are secreted which enable the plant to absorb vital nitrogen compounds and nutrients.
The more I looked, the more of these sundews I saw, nestled within mosses or sprouting from patches of exposed soil, lying in wait a bit like miniature spider webs. And I noticed many of their leaves had caught something and were clenched around the dead prey as it was digested, showing that their tactics certainly reap rewards.
Many also sported a bare upright stem which would have held aloft small white flowers during the summer.
The sundews – so named as their droplets resemble morning dew glistening in the summer sunshine – belong to the family drosereceae, which also includes the Venus flytrap. More specifically, sundews are part of the genus drosera, extending to nearly 200 species worldwide.
In the UK we have three species of sundew, and the one I had come across was the round-leaved sundew, our most widespread and common variety which, as the name suggests, has round leaves.
Apparently Darwin was a great fan of this species, studying it at great length and dedicating much of his 1875 book Insectivorous Plants to the sensitive trigger mechanisms at play.
The differing oblong-leaved sundew matches its description in appearance, the leaves tapering into the stems so that they resemble the heads of tennis racquets. And the rarer great sundew is much larger, favouring the wettest areas of bogs, and has leaves described in the excellent book The Wildlife of Dartmoor as being “like long rounded paddles”.
I had no luck finding anything but the round-leaved sundew, and at the second site I visited I was treated to plenty more. I won’t say exactly where, as some people dig them up, even though they are difficult to grow at home given the conditions they require and should definitely be left where they belong.
Dotted about among the moss and mud, these red plants brought to mind sea anemones, with tentacles spread wide. Traps set for hapless insects – even as large as dragonflies unable to pull free from the sticky tendrils.
A case of nature red in tooth and claw… and leaf.