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Carnivorous Plants
If the dirt in your
backyard is rich, black soil, you’ll probably see plenty of
dandelions, buttercups, and zinnias as you look around. But
something is missing. You won’t see any meat-eating plants.
You’ll only find them where there is wet, sandy soil. They love
to dig their roots into the sand, but sand doesn’t have
nutrients in it like backyard dirt. If these plants only got
food from the sand, they’d starve. The plant needs to get these
minerals somewhere other than the soil. They are carnivorous or
meat-eating plants. Instead of being food, the plant becomes
the hunter! Of course it doesn’t pick up its roots and look for
a nice meal. Instead, it lures insects into a deadly trap.
The most familiar carnivorous plant
is probably the Venus Flytrap. It has white flowers and traps
that can be as long as a few inches across. Each trap is a leaf
divided into two parts like a clamshell. It has little trigger
hairs on the inside and stiff spines along the outer edge of the
leaf. Inside the trap is a bright red color and sweet, sugary
nectar.
A fly hovers over top of the Venus
Flytrap, where it stands on the riverbank. It sees a bright
color below. Thinking it is a flower, the fly is attracted to
the color and taste. It lands on a leaf. The Flytrap quivers,
but the fly doesn’t notice. The fly crawls inside the trap,
brushing against those tiny hairs. This signals the trap and
the leaf snaps closed!
It seems funny, but the trap doesn’t
close completely at first. A small opening remains. The fly
tries to climb out, but he’s too large! On another Flytrap not
far away, a tiny mosquito lands. It brushes a trigger hair.
The Flytrap snaps shut. But the tiny mosquito climbs right out
of the opening and flies away. Don’t worry, the Flytrap didn’t
miss out on its meal. You see, even though a plant gets energy
from its meal, it takes a lot of energy for a plant to eat that
meal. It might take more energy to digest a small meal than the
plant would get back in return. If the insect is too small for
the plant, it will crawl away. The trap will open again the
next day and wait patiently for a larger meal. If the trap
catches an insect that is too large, that will also take too
much of the plant’s energy to digest. Instead, the trap dies,
turns brown, and falls off.
When a suitable meal is caught,
like the fly, the trap will close tightly and stay closed. The
leaves will close so tightly that they crush the fly inside. It
also creates a seal to keep liquids inside. The plant releases
its digestive juices which begin to break down and eat the
meat. The fly eventually turns to a nutritious liquid that is
absorbed by the plant. Afterwards, the trap opens and the
dried-up remains blow away.
** Facts and Activities to be posted
later
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