Mississippi Sandhill Crane National Wildlife Refuge
Conserving the Nature of America
A Savage Prairie - Carnivorous Plants

The carnivorous plants on the refuge grow in specialized wetlands called wet pine savannas. These habitats are seasonally flooded and remain wet for most of the year. Wet pine savannas get moisture from rainfall that collects on the clay soil surface, creating very muddy, soft soils that often pond.

Wet pine savanna soils are acidic in nature and have very low nutrient capacity. As such, the plants that grow in wet pine savannas are adapted for moist, high acid, low nutrient conditions. Some plants of the savannas make up the lack of nutrients in the soil by capturing, killing, and digesting animals -- mostly insects. These are called carnivorous plants.

The refuge is the home of 10 species of carnivorous plants that fall into four main groups:

 

Pitcher Plants

Pitcher plants have a unique method of capturing insects. The pitcher is actually a modified leaf and can hold water! Insects are attracted to nectar produced at the rim and on the inside of the pitcher.

As the insect crawls into the pitcher to get more nectar, it is trapped by downward pointing hairs that do not allow the insect to crawl back out. When the insect tires of trying to get out, it falls down into the base of the pitcher which is filled with digestive enzymes.

The pitcher plant uses the nutrients released from the insects. Look down into the pitcher plants you see on the refuge. You will see the many insects that have fallen prey to the mighty pitcher plant.

 
Pitcher Plants
     

Yellow Butterwort

 

The photograph of the pitcher plants above shows both the modified "pitcher" leaf and the flower. The flowers petals are more delicate in the spring, but instead of falling off, the petals turn hard and stick out from the seedpod like wings.

 

Butterworts

Butterworts and sundews capture prey on sticky, glue-like pads on their leaves. Insects are attracted to the sticky substance. Once they land on a leaf they are trapped by the glue. The leaf will roll up around the insect to encase it.

The plant will then release chemicals to digest the insect. The plant will absorb the nutrients released from the insect.

When the plant is done, the leaf will unroll and the insect exoskeleton will be released.

This particular species gets it's name from the yellow flower which is often the first bloom in spring (early March). The basal rosette of butterwort leaves grow right on the ground. The leaves feel slimy to the touch like butter.

     

Sundews

Like the butterworts, sundews capture prey on small sticky, glue-like pads on their leaves.

To the right, you see threadleaf sundew which is green, long and thin. You can see the tops of the leaves curled around their prey. In the spring, purple flowers make this plant more visible.

The red sundew is dwarf sundew. This photo shows the uncurling of its flower, seen only in the spring.

Because they are small, sundews and butterworts require careful observation as you walk through the savanna. But with a careful eye, you may see one of these plants with an insect trapped within it.

 
Threadleaf and Dwarf Sundews
     

Bladderworts

One of the most elaborate and specialized methods for capturing prey is seen in the bladderworts. This plant has small bladders that have a trap door on one end. When the bladder is empty, the door is closed. If an insect brushes against the small hairs on the door, it swings open. Water and insect rush into the bladder. The door closes, trapping the insect inside.

View the bladderwort below. Just the flower rises above the water. The bladders help it float in the water and you can see the root system where the small bladders are located.

The bladderworts are unfortunately one of the hardest groups of plants to see trapping prey on the refuge. The two species of terrestrial bladderworts have bladders below the soil surface to catch soil dwelling insects. The aquatic bladderwort, however, can be found in small ponds and water holes on the refuge.

Bladderwort
     

List of carnivorous plants on the refuge:

Scientific Name   Common Name
Drosera capillaris   pink sundew
Drosera filiformis   thread-leaf sundew
Drosera intermedia   spoonleaf sundew
Drosera tracyi   Tracy's sundew
Pinguicula lutea   yellow butterwort
Sarracenia alata   yellow trumpets pitcher plant
Sarracenia psittacina   parrot pitcher plant
Utricularia juncea   southern bladderwort
Utricularia purpurea   eastern purple bladderwort
Utricularia resupinata   bladderwort
Last updated: May 29, 2009