The wild world of carnivorous plants - Kenny Coogan

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Carnivorous Plants

Lesson by Kenny Coogan, directed by Lisa LaBracio.

Little do they know it,

but these six creatures are each about to
experience a very unusual death.

One-by-one,

they will fall prey to the remarkable,
predatory antics of...

a carnivorous plant.

Around the world there are more than
600 plant species

that supplement a regular
diet of sunlight, water, and soil

with insects, microbes,
or even frogs and rats.

Scientists believe that carnivory in
plants evolved separately

at least six times on our planet,

suggesting that this flesh-munching
adaptation

holds a major benefit for plants.

Carnivorous plants tend to grow in places
with highly acidic soil,

which is poor in crucial nutrients
like nitrogen, phosphorus, and potassium.

In these hostile conditions,

plants that are able to lure, trap,
and digest prey

have an advantage over those that rely
on soil for their nutrients.

Take this inhospitable bog,

where pitcher plants reign supreme.

Drawn to the pitcher’s vivid colors
and alluring scent,

the fly closes in and slurps its nectar.

But this pitcher species has an ingredient
called coniine in its nectar,

a powerful narcotic to insects.

As the coniine takes effect,

the fly grows sluggish, stumbles,
and falls down the funnel

into a pool of liquid at the base,

where he drowns.

Enzymes and bacteria in the liquid slowly
break his body down

into microscopic particles the pitcher
plant can consume through its leaves.

Occasionally,

larger prey also tumbles into the
fatal funnel of the pitcher plant.

The second victim faces off with the
sticky sundew plant.

The sundew’s tiny leaves are equipped with
a viscous secretion called mucilage.

The ant is swiftly trapped in this goo.

As she struggles, enzymes begin
to digest her body.

Special tentacles sense her movement
and curl around her,

clenching her in their suffocating grip.

Once she asphyxiates,

which can happen in under an hour,

the tentacles unfurl again
to snare their next victim.

Two down, four to go.

The next target meets his end underground,

in the coils of the corkscrew plant.

He enters the roots through a tiny slit
in search of food.

But inside, he quickly loses his way
through the tangled labyrinth.

A forest of curved hairs
prevents his escape,

guiding him into a central chamber
with flesh-digesting enzymes

and deadly low levels of oxygen.

In the murky depths of a nearby pond,

a tadpole unwittingly swims into the path
of the bladderwort,

the speediest of all carnivorous plants.

She treads on the bladderwort’s trigger,

and in milliseconds,

a trapdoor swings open and sucks her in.

Trapped half in and half out,

she struggles to free herself

while the part of her body inside
the plant gets digested.

Over the next few hours,

her writhing sets the trap off repeatedly,

each time bringing her deeper
into the plant

to be digested alive bit by bit.

Meanwhile, this beetle is bewitched by
sweet-smelling nectar.

The scent draws him closer and closer

until he lands on the leaves of the
world’s most infamous carnivorous plant.

His landing triggers tiny hairs on the
surface of the leaves,

and the jaws of the venus fly trap
snap shut around him.

The spikes interlock to seal his fate.

Once closed,

the leaves act like an external stomach
that digests the beetle’s soft tissues.

When they open again a few days later,

only the dry husk of his
exoskeleton remains.

The mayfly is the last creature standing.

As she approaches the butterwort plant,

she heads for the flowers that wave high
above the plant’s globs of adhesive goo.

She alights on the petals, drinks the
nectar, and takes off unscathed.

These long flower stalks keep certain
insects away from the carnivore’s traps—

a way of separating pollinators from food.

Off the mayfly buzzes
to live a long and fruitful life–

oh.