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Wildlife Wonders

Today is Carnivorous Plant Day!

Carnivorous plants are “meat eating” plants.  There are over 630 different “species” of carnivorous plants and they have different methods for trapping their “prey”.  The different types of traps include:

1.  Pitfall traps – pitcher plants. Insects fall into fluid in the plant and drown.

2.  Flypaper (sticky or adhesive) sundews and butterworts

3.  Snap traps – Venus flytrap

4.  Suction traps – bladderworts.  The traps are underwater and like using a straw it sucks up an insect. 

Today we will focus on the Venus flytrap.  The Venus flytrap is a rare plant and is found on the “endangered species list”.  It is only found in North Carolina and South Carolina in boggy areas (a type of wetland habitat).  Although there are not many of them, due to poaching and loss of “habitat” because of development, they have been around for 65 million years!  Venus flytraps were around when the dinosaurs roamed the earth. Venus flytraps grow in sandy soil, that doesn’t have a lot of “nutrients”…it isn’t healthy for them so they need “supplements” or “vitamins” to help them grow. Because of this they have bizarre “adaptations” for eating insects and other forms of “meat”.

The entire plant is about 5 inches in diameter (less than the length of a dollar bill, that is 6 inches).  They usually have six stems with hinged leaves (about 1 inch).  Each leaf has a reddish lining and they secrete a fragrant, sweet nectar that lures the insect over.  Although they are called a Venus “fly”trap, they mostly eat ants, but they will also eat flies, beetles, slugs, spiders and on rare occasions tiny frogs!

So the leaves are wide open and an ant comes over because it smells something nice and sweet.  There are short, stiff hairs, known as trigger hairs inside the leaf and if the “trigger” hairs are touched, with the blink of an eye (1/10 of a second), the leaf snaps shut trapping what is inside (this is caused by a release of pressure in the leaf cells)!  Cool thing is if it isn’t food, let’s say a pebble fell inside, in about 12 hours it will open back up and spit it out.  Also, to make sure the insect is large enough to be worth eating, it doesn’t immediately shut all the way so very small insects can escape.

On the edge of the leaf there are “cilia”, finger like projections that keep larger insects inside.  These are like the bars on a cell to trap the insect inside.  (Fold your hands together and snap them shut!) 

Just like your stomach secretes fluids to break down your food, the plant does the same.  This dissolves the softer inner parts, but things like the “exoskeleton” of insects cannot be dissolved so after 5-12 days, when the leaf opens back up, anything that cannot be digested just blows away.  The leaf will do this a few times, and then it will wither up and fall off, only to be replaced by another leaf.

Venus flytraps are “perennial” plants – they bloom year after year, can live for 20 years or more and reproduce with seeds.  They can also reproduce from underground shoots called “rhizomes”.  They bloom in May or early June and have delicate white flowers.  Funny thing is they also need insects to help “pollinate” them.  So although insects are helping the Venus flytrap make more plants, they also make a meal out of them!

Venus flytraps are very rare and it is against the law to pick them.  The only place in the world where they can be found is in North or South Carolina, but they are easy to grow and many greenhouses sell them.  You can grow them in a terrarium, making sure they have plenty of sunshine and humidity.  Remember if they don’t have live insects to eat and you are feeding them dead insects you will need to make sure to touch the “trigger” hairs.  (Hamburger is not good for them because it takes too long to digest.)

Cool facts about other carnivorous plants:

1.  Unlike Venus flytraps another carnivorous plant, the pitcher plant, can be found in wetlands in the eastern United States, from Florida to Nova Scotia and across Canada to the base of the Rocky Mountains.  Sundews, pretty insect eating plants, are found in most of the United States, except some portions of the Southwest.

2.  Mosquitoes are not affected by the digestive juices of the pitcher plant.  The adult mosquito lays her eggs in the fluid, where the larvae develop and feed on trapped insects.

3.  Insects are attracted to the sweet smelling nectar of the sundews.  They become stuck to the gluey balls that look like dewdrops on the plant and once the plant feels the insect struggling, it slowly encloses the insect in its tentacles and smother it. In minutes it secretes digestive juices and the insect starts to dissolve.

Resources:

  • Hungry Plants by Mary Batten, illustrated by Paul Mirocha
  • The Venus Flytrap’s Lethal Allure by Abigail Tucker, Smithsonian Magazine, February 2010
  • Facts About Venus Flytraps by Alina Bradford, Live Science, February 25, 2017

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