I’m not much of a botanist, but for the provincial flower of Newfoundland & Labrador I’m prepared to make an exception. The lilies and irises of mainland Canada are all very nice, but they can’t hold a candle to a carnivorous plant.
What Sarracenia purpurea reveals about the way the province perceives itself, I’m not sure, but as a subverter of the natural order of things, perhaps it is appropriate. With contrary feeding habits and an ability to eke out a living on unforgiving terrain, the purple pitcher plant is surely a true Newfoundlander.
Whilst a fog-hating, food-hunting human can always move, though, it’s a bit trickier for a plant. Becoming less fussy in what one consumes is one thing, but transforming oneself into a meat-eater is another thing entirely, and a life choice that deserves a closer look.
Carnivorous plants: more common than you might think
Carnivorous plants are found in places where water and light are readily available but the soil is low in the nitrogen they need for growth. To get their dietary supplement, they have turned to catching live prey, and carnivory is surprisingly popular: over 600 species have evolved the ability.
These vegetants have become vicious in an ingenious range of ways. From the super-sticky secretions of sundews to the sudden, terminal embrace of the Venus fly-trap, it’s easy to see why Charles Darwin was so enamoured of them. “This is in every way a remarkable phenomenon,” he wrote in his book Insectivorous Plants, “for the leaf [of the fly-trap] falsely appears as if endowed with the senses of an animal.”
Even forms that look similar are deceptive. There are two groups of pitcher plants – one in North America, one in tropical Asia – but a love of blood does not make them brothers. The tropical forms (some of which are giants capable of swallowing prey as big as frogs), are more closely related to cacti and carnations than they are to the purple pitcher plant.
Improbable though it might sound, meanwhile, its genetics show Sarracenia shares greater kinship with azaleas and the Brazil nut tree. The evolution of carafe-shaped leaves is just convergent problem-solving.
To figure pitcher plants out, then, you have to rely on careful scientific analysis. In most species, the deep, slippery-sided, hollow leaves – known as pitfall traps – contain enzyme-rich waters. The flower’s colour and scent lures insects in, they step unwisely beyond the leaf rim, slip into the acidic pool, drown, and get dissolved.
A pitcher plant unlike others…
Sarracenia purpurea is not like most pitcher plant species, though. It can lure insects in, but its leaf-waters aren’t especially rich in digestive juices, so it struggles to drown and dissolve them. Instead, by creating a pitcher-perfect habitat, the hungry plant gets others to do its dirty work for it.
The live-in caterers range from bacteria and rotifers to flesh-flies and mosquitoes. The larvae of the bigger beasts are especially critical to the pitcher plant, for they work as its butchers. When a bug falls into the trap, they swim over, kill it, chop up the meat into manageable chunks, eat it, digest it, and excrete the remains.
Down the food web, scavenging and detritus-loving organisms then break the meal down further, and the pitcher plant is finally able to absorb the resultant nutrients. It’s a strange kind of soup kitchen, but it serves an amazing array of customers. In total, across North America, the pitchers of Sarracenia contain almost 100 other species, and in Newfoundland, a single plant can have 40 different types of lodger.
As extraordinary as this flourishing is, the kitchen is – first and foremost – a death trap. Many different animals perish there; to purple pitchers in western Newfoundland, ants, flies, snails, slugs, and beetles are the most popular servings.
That said, the purple pitcher plant is not a very efficient trapper. A study of a population in New Jersey revealed they have a catch success rate of less than 1%. Ants might appear a popular snack, but of 2,470 that were recorded entering the pitchers, 2,405 came out again unscathed!
However, with the volume of arthropods swarming around the province in the summer, there’s no shortage of dining options. It might not be the greatest hunter, but Sarracenia purpurea does pretty well for itself: some individuals can live for 50 years.
And anyway, even if they’re not the greatest of meat-eaters, the fact they’re meat-eaters at all is fascinating, and there are many more secrets still to uncover. An example of this was published only a few months ago, when some carnivorous plants were shown to fluoresce. The provincial pitcher turned out to be not just purple, but ultraviolet.
Since various insects can see in that wavelength of light, invisible to us, this previously unrecognized weapon might be another way of attracting prey. It’s funny to think it, but in a fashion, purple pitcher plants could be doing what our bug killers do: tempting insects in with an attractive glow, then delivering a knockout blow.
So, does this also mean the barrens of the Avalon or Gros Morne have an eerie nocturnal illumination? Well, you’d have to take the right kit out with you to find out, but if you haven’t already, maybe then you’d see the extraordinary provincial flower in a whole new light.