The famed naturalist Charles Darwin called the Venus flytrap "one of the most wonderful [plants] in the world."
By Stuart Thornton
Monday, August 29, 2011
On a balmy summer Sunday morning in Carolina Beach State Park in North Carolina, assistant park ranger A.J. Loomis leads a guided hike on the half-mile-long Flytrap Trail. On the trail, Loomis and park visitors uncover one of nature’s most interesting oddities: carnivorous (meat-eating) plants.
Before coming to the most popular of the carnivorous plants, the Venus flytrap, Loomis leads the group to the end of a wooden boardwalk overlooking a patch of sundews and a pitcher plant.
About the size of a quarter, the red sundews have sticky droplets that attract insects to their leaves, where hairs fold over the prey and begin the digestion process.
“We have more of these than any other carnivorous plants,” Loomis says.
Just a few feet away, the larger pitcher plant has a long, trumpet-like tube that rises from the ground. The plant secretes a sweet smell that entices insects to travel down into the plant’s tube, where they are unable to escape.
“This thing is so efficient to the point it can almost overflow with [insect] skeletons,” Loomis says.
After passing by wax myrtles and a coast live oak nestled in the park’s sandy soils, Loomis takes the crowd to a small collection of Venus flytraps. They appear like tiny green catcher’s mitts just above the ground. Though Venus flytraps have been planted in other regions, they only appear naturally within a 95- to 115-kilometer (60 to 70 miles) radius of Wilmington, North Carolina.
“It’s endemic to this area,” Loomis says. “It’s naturally growing here for one reason: The soil is so poor.”
The soil is the reason the Venus flytrap is a carnivorous plant. The flytrap digests insects to supplement the low amount of nitrogen and phosphorus it receives from the region’s sandy, acidic soil.
The plant’s trap is a single large leaf with trigger hairs. When a fly or ant brushes against one of the leaf’s trigger hairs two times, the plant folds its leaf quickly, trapping the prey inside. Then, the Venus flytrap secretes a digestive fluid that helps the plant absorb nutrients from the trapped insect. It takes three to five days for the plant to digest the organism. Only then will it open its leaf again.
“It can go months without catching anything,” Loomis says.
Each leaf-trap can open and close three times before dying and falling off the plant. The old trap is replaced by a new one from the Venus flytrap’s underground stems.
Loomis points to a red coloring on the inside of some of the plant’s traps. “It’s a sign that it’s healthy,” he says. “It can also lure insects into them.”
While individual Venus flytraps are healthy, the overall population in Carolina Beach State Park is low this year. Park ranger Carla Edwards says that last year she counted about 400 Venus flytraps in the 280-hectare (700-acre) park. This year, she suspects there are only 250 to 300 plants. Edwards says some have died because of excessive heat and lack of precipitation.
But the main threat to the population of Venus flytraps is poachers. Poachers sell the plants to nurseries and gardens, where they fetch high prices.
Edwards estimates poachers have dug up about 100 plants. Park staff have thought about putting up wildlife cameras to capture the poachers, but at this point, they are just trying to make people aware of the problem.
Other Carnivorous Plants
In addition to Venus flytraps, sundews, and pitcher plants, there are two other types of carnivorous plants in Carolina Beach State Park. The butterwort is a plant with purple flowers that catches prey on its sticky, greasy leaves. Once stuck, the insect is digested by the acid in the slimy substance coating the plant.
Another carnivorous plant is a bladderwort, which has both aquatic and terrestrial varieties. The aquatic bladderworts grow in the park’s Cypress Pond and Lily Pond, while the terrestrial bladderworts pop up on land around the bodies of water. The plant’s “bladders” are air-filled balloons with trap doors. As an insect releases the trap door, water fills the bladder, sucking the insect in with it. The bladders are not part of the leaves or stems of the plant, Edwards points out.
“The trap part of the bladderwort is in the root system,” Edwards says. “There are small bladders on the roots. Each bladder has a trigger hair on it. When something touches the hair, it sucks its prey in.”
Carolina Beach State Park is just one place in the Wilmington area to view carnivorous plants. Venus flytraps and other meat-eating plants can be found at the Herbert Bluethenthal Memorial Wildflower Preserve (part of the University of North Carolina at Wilmington), Airlie Gardens, Lake Waccamaw State Park, and the Green Swamp Preserve near Supply.
Term Part of Speech Definition Encyclopedic Entry absorb Verb
to soak up.
chemical compound that reacts with a base to form a salt. Acids can corrode some natural materials. Acids have pH levels lower than 7.
having to do with water.
mild and pleasant.
carnivorous, or meat-eating, plant.
small, carnivorous plant with sticky leaves.
coast live oak Noun
shrub-like tree native to western North America. Also called the California live oak.
to convert food into nutrients that can be absorbed.
digestive fluid Noun
natural secretions that help break down food as part of the digestion process.
native to a specific geographic space.
to lure or attract.
too much, or more than usual.
to walk a long distance.
type of animal that breathes air and has a body divided into three segments, with six legs and usually wings.
organ growing from the stem of a plant.
animal flesh eaten as food.
to live or be located in a safe, sheltered spot.
chemical element with the symbol N, whose gas form is 78% of the Earth's atmosphere.
place where plants are raised for research or sale.
substance an organism needs for energy, growth, and life.
Encyclopedic Entry: nutrient phosphorus Noun
chemical element with the symbol P.
pitcher plant Noun
carnivorous plant with a long tube filled with liquid, which traps and drowns insects.
organism that produces its own food through photosynthesis and whose cells have walls.
person who hunts or fishes illegally.
total number of people or organisms in a particular area.
all forms in which water falls to Earth from the atmosphere.
Encyclopedic Entry: precipitation prey Noun
animal that is hunted and eaten by other animals.
any area on the Earth with one or more common characteristics. Regions are the basic units of geography.
Encyclopedic Entry: region root system Noun
all of a plant's roots.
to discharge a substance.
bones of a body.
top layer of the Earth's surface where plants can grow.
main stalk of a plant.
carnivorous plant with sticky hairs that trap insects.
to increase or add to.
having to do with the Earth or dry land.
Venus flytrap Noun
carnivorous plant that traps and consumes mostly insects.
wax myrtle Noun
tree or shrub native to southeastern North America.