Predator plants: how N.W.T.'s carnivorous vegetation snare their prey

Nature enthusiast Jeff Hollett shares some of the trapping techniques, such as death by gobs of goo, used by Northwest Territories' carnivorous plants.

Plants like bladderworts and sundews eat insects and other creatures for extra nutrients

Suffocated in slime. Drowned and dissolved in a deep cauldron of death. Snatched-up, sealed-in, and soupified in a sepulchral sack of enzymatic slurry.

The above may seem like an excerpt from a medieval executioner's to-do list (one with a propensity for alliteration), but it's actually a description of how some carnivorous plant species here in the N.W.T. trap and consume prey.

While the outlaw Albert Johnson may have earned the title The Mad Trapper for his legendary N.W.T.-to-Yukon run from the law in 1932, he certainly isn't the only mad trapper the N.W.T. has produced. In fact, in my view, our carnivorous plants easily out-mad Mr. Johnson.

After all, gun fights seem downright pedestrian when compared to the enzyme-laced death tentacles of a sundew plant.

Carnivorous plants are animal eaters. They capture and consume prey such as insects, spiders and crustaceans as a way of securing nutrients unavailable from the nutrient-poor soil or water in which they grow.

There are four groups of carnivorous plants in the N.W.T.: pitcher plants, sundews, bladderworts, and butterworts.

Of these, the bladderworts stand out in terms of trapping ingenuity and ferocity. They are truly the maddest trappers of them all!

Bladderworts are a genus of carnivorous plants that live in freshwater or saturated soil. The N.W.T. has four species of bladderworts; all inhabit shallow ponds with slow moving water.

The largest portion of an aquatic bladderwort plant lies beneath the surface of the water where its stems are covered in tiny bladders that act as prey traps. When an unsuspecting prey organism touches hair-like triggers attached to the bladder trap door, water is sucked into the bladder, taking the prey with it.

Greater bladderwort flowers rise above the pond surface. In the N.W.T., this species typically starts blooming in late June. (Jeff Hollett/CBC)

Incredibly, this process occurs in less than a millisecond and with an acceleration of up to 600 G!. To put this in perspective, humans will pass out at just 8Gs.

Each trap can be fired over and over again such that a single plant can trap thousands of tiny organisms in a single day. After being trapped, prey organisms inside the bladders are dissolved with digestive enzymes and absorbed by the plant.

Because the bladders are small (1.2 cm or less), prey organisms are typically small as well, and include such things as water fleas, rotifers and small insect larvae. Some bladderworts, however, can capture larger prey such as tadpoles or fish fry.

These larger organisms are typically captured by the tail. The plant dissolves and absorbs the tail section lodged inside the bladder while most of the prey organism remains on the outside – still alive! The plant eventually takes the remainder of the prey into the bladder until most or all of it has been eaten. Gruesome, or what?

While bladderworts are the maddest of the photosynthesizing trappers we have in N.W.T., our other carnivorous plants are no slouches in the meat-catching department, either. Sundews (three N.W.T. species) and butterworts (two N.W.T. species) are nature's fly paper.

This prey will make a nice meal for the roundleaf sundew plant that caught it by the abdomen. (Jeff Hollett/CBC)

Sundew leaves are covered in long, glandular tentacles that secrete sticky mucous to trap, kill and digest prey. Once triggered, the tentacles bend inward and around the prey, maximizing the plant's ability to hold, kill and digest the organism.

Similarly, butterworts have special glands on the surface of their broad leaves that secrete prey-ensnaring mucilage. Upon contact with an insect, glands are triggered to produce even more mucilage which eventually encases the prey — in other words, death by gobs of goo.

Last, but not least, the N.W.T.'s sole pitcher plant species, the purple pitcher plant, uses yet another mechanism to trap prey. Modified leaves form tall pitchers that fill with rain water and act as drowning chambers for prey organisms that are attracted to these structures by secretions of nectar.

The mouth of each pitcher is slippery, causing some insects to fall into the water below where they drown, are dissolved, and eventually absorbed by the plant.

The N.W.T.'s carnivorous plants can be observed throughout much of the summer. In addition to being mad trappers, they're also quite beautiful.

Our bladderwort species, for example, produce beautiful yellow flowers somewhat reminiscent of snapdragons or orchids, and many are in bloom right now. The mucous-tipped, bright red tentacles of sundews are a beautiful sight up close, and pitcher plants are captivating for their colourful, uniquely shaped pitchers as well as for their large, leathery flowers. Check 'em out!


Jeff Hollett is a nature enthusiast and amateur photographer who has lived in the Northwest Territories and Nunavut for much of the past 25 years. He currently resides in Yellowknife with his wife, Karen, and their dog, Spot.