On the top floor of the Weber State University Science Lab Building is a greenhouse, WSU’s own little shop of horrors. Inside the greenhouse are various species of carnivorous plants.
Carnivorous plants are flora that derive some if not most of their nutrients from insects and protozoa. While the harmless-looking plants are almost hidden in the greenhouse, the dead gnats stuck to their leaves give them away.
“They have a nectar that lures in insects,” said Sonya Welsh, the botany lab manager. “There was a study done that says that some of the plants emit a light on the UV spectrum. Insects see within that spectrum and it lures them in.”
Carnivorous plants can be a good indication of the quality of soil in the natural environment.
“You know, carnivorous plants are not technically carnivorous, as they break down other organisms’ bodies for their nitrogen, not calories,” said Cynthianne Hecklesmiller, WSU botany major and the Botany Club president. “This means that they are a good indicator of nitrogen-poor soil; they can thrive in it, because they don’t have to compete for soil nitrogen. That’s why it was so cool to see them growing in their native environment. I was able to understand a little more about the bog they were growing in because of their presence.”
WSU’s greenhouse is currently home to seven different types of carnivorous plants: Asian pitcher plants, Mexican butterworts, North American pitcher plants, sundews, bladderworts, Venus flytraps and Australian pitcher plants. However, these are not the only carnivorous plants the greenhouse has seen.
“Previously, we have grown cobra lily, sun pitchers from South America, rainbow plants, Portuguese sundew, Roridula and a carnivorous bromeliad,” said professor Blake Wellard, the on-campus expert on carnivorous plants.
There are more than 600 species of carnivorous plants worldwide, which are split among 12 genera.
Flypaper traps like sundews and butterworts depend on their sticky hairs to trap prey. The hairs secrete enzymes that break down the prey into nutrients for the plant. Some species of sundew envelop the prey with their leaves to help increase the rate of digestion.
Pitfall traps, like the ones grown in the WSU greenhouse, have colorful markings that lure prey to the nectar dangerously positioned above a pit of digestive juices. The areas around the pit are slippery and can cause the insect to slip to its death.
Snap traps, like the Venus flytrap, use sensitive hairs that trigger the trap to snap shut when the prey makes contact. Vacuum traps, another type of trap, are used by aquatic and terrestrial bladderworts. Once the prey triggers the sensitive hairs, it is vacuumed up.
Plants take different amounts of time to digest their victims. It can take anywhere from four days to several months, depending on the type of plant.
“Pitfall traps, such as the North American pitcher plants and Asian pitcher plants, can capture and digest numerous prey simultaneously,” Wellard said. “Sometimes these traps are so successful at capturing prey that they often tip over or overfill with dead insects. The best way to think about these plants is that they function like the sarlacc, or pit monster, from ‘Star Wars.’ These plants slowly digest their victims for up to several months.”
Although the prey tends to be rather small, according to Welsh, the plants aren’t necessarily picky about their food.
“If a small mouse falls into one of the pitchers, it’s going to digest it.”
While carnivorous plants can be found all over the world, some of them call Utah home.
“Utah has three native bladderworts, and with additional exploration, botanists may find sundew growing in high mountain wetlands,” Wellard said.
Unlike in the movie “Little Shop of Horrors,” which centers on a man-eating plant, humans have little to worry from these plants.
“Unless a great botanical explorer discovers the legendary man-eating tree from Madagascar, there is not a known species that poses a great threat to human existence,” Wellard said. “If we can give carnivorous plants a few million years to evolve, they just might inherit the earth.”
The WSU Department of Botany has already started growing carnivorous plants to sell in April for the department’s plant sale.