Carnivorous Plants: Science Fiction or Science??

What in the world is a carnivorous plant? Must be able to attract,

capture and kill animals (mostly insects)

Also must digest the animal Can survive without eating

meat, though. Most are small (<1 m tall)

but one vine species can grow to be 10 m long

Where in the world can I find these plants?

Everywhere except Antarctica!! More abundant in Australia, southeast

Asia and North America Even Alachua county has them!! 600 species and sub-species, but not all

related to each other

Where in the world can I find these plants?

Hundreds of species of plants from several genera are carnivorous.

Carnivorous plants are found all over the world.

Their habitats range from grasslands to swamps to under water, from civilization to the jungles of the Amazon.

Why aren’t all plants meat-eaters?

Carnivorous plants have an advantage over non-carnivorous plants in nutrient poor habitats

In habitats with more nutrients, non-carnivorous plants do better because they do not have to put energy into special structures.

What animals do they eat? Mostly Insects and spiders

(gnats, flies, moths, wasps, spiders, butterflies, beetles and ants)

Freshwater species eat small water animals and fish and mosquito larvae

Some capture small amphibians (frogs) and small birds and rodents have been found in some tropical species!!

Some species even eat insect and bird excrement!!

How do these plants capture prey?

Can be sweet-smelling or brightly colored to attract prey to their trap

There are 2 types of traps Active: Use rapid

movement (ex. Venus fly-trap, Utricularia)

Passive: sticky hairs or a long tube with hairs that trap prey

Active or Passive?

How do they digest their prey?

Most produce digestive enzymes

Some rely on bacteria Some use both

bacteria and digestive enzymes

What habitat do they live in? The genus Utricularia is

aquatic (freshwater) Mainly found in nutrient

poor wetlands (ex. Bogs) Decaying plants release

acidic compounds Microorganisms cannot

function Difficult for plants to get

nutrients from acidic soil

How do we affect carnivorous plants Only 3-5% of carnivorous

plant habitat left! Draining wetlands

For roads, homes, stores and water

Suppressing fire Many ecosystems need fire

to stay healthy Pollution from homes and

agriculture Gets into water and destroys

plants Poaching the plants: Many

are endangered.

Are The Plants Hard to Grow? Carnivorous plants

can be easy to grow. They can be

cultivated in a greenhouse.

You can grow some varieties in your house as house plants!

How do Carnivorous plants get their energy?

They get their energy the same way the other plants do...

Photosynthesis

Why do Carnivorous plants eat insects and other small animals?

They eat insects and other small animals because they live in places where the soil is low in nutrients.

Carnivorous plants get the needed nutrients from their “PREY”.

A CLOSER LOOK

Catching the insect

The actual traps are located on the plants leaves They attract their victims with a scent reminiscent of

food and a safe landing place As soon as the insect settles, the leaf tips spring

instantly with lightning speed and within seconds the insect is trapped inside the two halves of the leaf

There is a second where the plant tests what it has caught using its sensory glands on the surface of its lobes

If the prey contains protein, the trap clothes fully and the digestion begins

The Digestion Process

Once the insect has been caught, it is slowly dissolved by digestive fluids produced by the plant

After many days, all that is left is the insect’s exoskeleton, the hard outer casing of the body

The rest has been absorbed by the plant

Vitamin Tablets Carnivorous plants, like any other plant, also

use the process of photosynthesis to make their own food

The insects they catch are only used as dietary supplements

Like the equivalent of vitamin tablets for plants Many plants need this extra source of food as

they grow in waterlogged ground where the soil is lacking in nutrients and other essential nutrients

What types are there?

Pitfall Traps(pitcher plant)

The pitcher plant is basically a slippery leaf wrapped into a tube shape that contains a pool of digestive enzymes at the bottom.

Pitfall Trap (Cobra Lily)Most Pitfall Traps have the opening on the top of the plant, the Cobra Lily has an opening on the bottom. When an insect flies into it, it has “windows” that let light in but not insects out. The insects are attracted to the light but cant get out.

Cobra Lily Video http://www.youtube.com/watch?v=oqo-75xZ15M

Fly Paper traps(sundew)

Fly Paper traps are coated with a sticky substance called “mucilage". When an insect lands on the plant it sticks to it, after a while the plant will curl around it and digest it.

Snap traps(Venus fly trap)

Venus Fly Trap has small trigger hairs on the inside, so if an insect lands on it and triggers only one hair and flies off its lucky but if it triggers more than one it will cause its own doom.

Bladder traps(Bladderwort)

The Bladderwort is like an under water Venus Fly Trap. The bladders suck in and trap water insects.

Let’s Review. . . 1) What are the 4 traits of a carnivorous plant? They attract, capture, kill and digest animals2) Do non-carnivorous plants share any of these traits? Non-carnivorous plants can attract insects 3) Do they need to eat meat to survive? No-they have been grown in labs without meat4) Where in the world can you find these plants? Everywhere except Antarctica5) How many species are there? Are they all related? 600 species and sub-species; they are not all related (convergent evolution)

Let’s Review. . .

1. What is the most common habitat of carnivorous plants?Nutrient poor wetlands.

2. What feature of their habitat allowed them to evolve carnivory?

The lack of nutrients available in the soil.3. Why does the habitat have this feature?

pH of water is low, so bacteria cannot help decompose plants and plants cannot take up nutrients as easily.

4. Why do non-carnivorous plants do better in habitats with more nutrients? Because they do not have to put energy into special structures to capture prey like carnivorous plants do.

Let’s Review . . . 1. What do carnivorous plants commonly eat? Insects, spiders and aquatic plants eat small animals, fish

and mosquito larvae. 2. Name 3 less common things they have been found to eat. Amphibians, birds and rodents 3. What are the two types of traps they use to catch their

prey?Active and passive

4. Name a variation of each type of trap. Active: bladderwort (Utricularia), venus fly trap

(Dionaea). Passive: pitcher plant has a pitfall trap; most carnivorous plants have sticky hairs.

Final Review and Wrap-Up1) What are the 4 traits of a carnivorous plant? Do non-carnivorous

plants have any of these traits? Attract, capture, kill and digest animals. Yes, many plants attract

insects for pollination. 2) How many species are there of carnivorous plants? Are they all

related? 600 species and sub-species that are not all related (convergent

evolution) 3) In what habitats and parts of the world are they found? Found mostly in nutrient poor wetlands everywhere except

Antarctica. 4) What feature of their habitat allowed them to evolve carnivory? Lack of nutrients

Final Review and Wrap-Up cont…1) What are some of their common prey species? Some less common

ones? Insects and spiders. Less common are amphibians, birds and rodents.2) What are the two ways they capture their prey? Active and passive traps. 3) How do they digest their prey (hint: what do some use to help them

digest?)? Some secrete digestive enzymes, some use enzymes and bacteria to

help them digest (symbiosis). 4) How have humans affected carnivorous plant populations and their

habitat? Humans have drained wetlands, suppressed fire, polluted water, used

too much water and poached plants.

Assignment

Draw your own carnivorous plant using only plant parts.