A Study Of Carnivorous Plants Essay, Research Paper
A Study of Carnivorous Plants
What exactly are carnivorous plants? They have made appearances in countless movies, books, and science fairs, but what defines a carnivorous plant is that an essential part of its diet is meat or insects. This includes venus flytraps (Dionaea muscipula), Pitcher Plants (Sarrecenia, Nepenthes, and Darlingtonia), and Sundews (Drosera).
Why must these plants “eat” meat? As plants and animals evolve, they change to thrive in their environments more effectively. These plants evolved in areas with extremely poor, acidic soil. To make up for this lack of nutrients, these plants developed ways to trap insects which would provide the nutrients required (Meyers, Rice B.A., www.sarrecenia.com/faq.html, 1998, Carnivorous Plant FAQ v6.0, Oct. 19, 1998).
The best known of these plants is the Venus flytrap, which uses a rather gruesome method of ensnaring its food; it has small “mouths”, which are actually leaves adapted to function as traps, that close over the insect and then dissolve it over a period of a few days. This is particularly fascinating as one can actually see the mouths close over the insect. But how does the mouth close? Plants lack muscle; it must use a slightly more roundabout way of capturing its food. The Venus flytrap uses water movement to its advantage; when something springs the trap, hormones are quickly released by the sensor cells which cause water to move out of the joint; this makes the leaf collapse over the insect, trapping it for digestion (Meyers, Rice B.A., www.sarrecenia.com/faq.html, 1998, Carnivorous Plant FAQ v6.0, Oct. 19, 1998).
The Sundew also moves, although it uses a different technique; when an insect is captured, the hormones that are triggered slow the growth of cells on one side of the leaf, while speeding up the growth of those on the other. This causes the leaf to curl up around the insect. A Sundew traps the insects on sticky spines, so it can take its time in digestion(Meyers, Rice B.A., www.sarrecenia.com/faq.html, 1998, Carnivorous Plant FAQ v6.0, Oct. 19, 1998).
The pitcher plants use a tube-shaped stem filled with a weak digestive enzyme to capture its prey. When the insect falls into the “pitcher”, it becomes trapped in the enzyme and is digested. The pitcher plant also has a leaf that shields the enzyme from rain, which would dilute the solution. (FEIS Biological Archive, www.fs.fed.us/database/feis, Oct. 19, 1998)
So, what impact do these plants have on the human race? Well, aside from their economical value to nurseries and hobbyists, they are important indicator species. In a scientific journal by Mary-Jo Godt, she observed that in areas of Florida, endangered species of Sarrecenia were dying out due to over-development; these plants will show when we are pushing the limits on our ecological systems before we cause any serious, permanent damage. (Godt, Mary-Jo(1998). The American journal of Botany, Allozyme diversity in the endangered Pitcher Plant Sarracenia, New York: Hamwick)
Besides being indicator species, these plants also play an important role in many marsh ecosystems. Drosera are used for forage by moose in the Kenai peninsula, are important to the continued existence of the marshes in which migratory waterfowls, among other creatures, live and mate, form a primary habitat for an endangered species of rattlesnake in Massachusetts, the eastern massassauga rattler, and are important sources of food for ants, which will opportunistically feed on the insects trapped on its leaves (www.cs.waikato.ac.nz/~trigg/, Oct. 19, 1998).
They can also be used to regenerate bogs, swamps, and wetlands that have been destroyed or damaged by industrial use or peat mining due to the fact that they are much more resilient than other carnivorous plants; one example of this is an Ontario bog that had been stripped two meters in peat mining. It is presumed that they help cycle nutrients back into the damaged, nutrient deficient soil by converting insects directly into useful substances. They can also be put to this use in areas damaged by burning or road construction. The leaves of Drosera can be used in the production of cheese as they have the natural ability to curdle milk; this technique is put to use in Sweden even today. The fresh leaves contain an antibiotic that has proven effective in the combat of several bacteria (i.e., Streptococcus, Staphylococcus, Pneumococcus) and has been used to treat respiratory diseases and warts(FEIS Biological Archive, www.fs.fed.us/database/feis, Oct. 19, 1998).
Unfortunately, Drosera rotundifolia, the round-leafed Sundew (the most useful of the species) is endangered due to drainage, which destroys insects that it will prey upon while they are still in the larval stage. They are also threatened by fertilizers and herbicides, which stunt the plant’s growth, and by the destruction of wetlands to increase property values. However, this plant has proven quite resistant to heavy grazing. This plant is found all around the temperate regions of the earth, so total eradication is not an immediate threat if preservation efforts are taken. It is found in Wisconsin(FEIS Biological Archive, www.fs.fed.us/database/feis, Oct. 19, 1998).
The next plant that influences the world we live in is the Pitcher Plant, or any Sarrecenia, Nepenthes, or Darlingtonia.
Darlingtonia californica, or the California Pitcher Plant, emits a putrid smell when damaged or cut, and is therefore an undesirable source of food. It is, however threatened by collectors, who will poach this plant from the wild and then sell it as a curiosity. It is an invaluable indicator species of the ecosystems in Oregon and California. It can grow up to 39 inches tall, which makes it an incredible spectacle, although most plants will only grow to be 8 to 24 inches tall.(www.waikato.ac.nz/~trigg/, Oct. 19,1998) This particular plant produces its own water, shielding outside water with a “hood”. Many of the insects that visit the plant will drink its nectar and escape uneaten, which creates a beneficial relationship between the plant and the insects, an integral part of the function of an ecosystem. The insects that do get trapped are decomposed by bacteria, as this particular species produces no enzymes for digestion. Some insects will actually live inside the pitcher, feeding off of the victims that fall in or come too close. This plant is considered an indicator of poor, serpentine-rich soil.
Sarrecenia Minor, or the Hooded Pitcher Plant, is found in the South-East corner of the United States and reaches through Georgia and Florida. It has a helmet-shaped hood to keep water out. Its main mode of propagation is through seed; however, it will regenerate if fragmentation of the rhizomes should occur. Bare ground is a necessity for the development of seeds. This species is threatened by collectors as well, and local extinction can occur. These plants also have a symbiotic relationship with many insects, providing the insects with nectar and eating the occasional careless feeder. (www.flytrap.demon.cc.uk/plant.html, Oct. 19, 1998)
Yet another pitcher plant, the Sarrecenia purpurea is slightly more widespread than its relatives. It is found in 36 states including this one. Its hood is positioned vertically, allowing rainwater to fall in. Its color can be anything from yellow to purple. It is a typical Pitcher Plant, able to propagate through rhizome fragmentation, but using seed as the main method. Bees are the main carriers of the pollen. They thrive in poor soil lacking minerals such as Molybdenum, and are a good indicator of where not to grow corn, oranges, or anything else that cannot live in driveway gravel. They share the same symbiotic relationship with insects that the other species enjoy with one notable addition; a small, non-biting species of mosquito lays eggs which grow into larvae exclusively in the liquid contained in the pitcher of this plant. Its diet contains a few interesting additions as well, including but not limited to snails, crickets, and grasshoppers. These plants help prevent cat tail overpopulation; in areas where this species of pitcher plants was damaged by salt runoff from the road, cat tails infested and choked the wetlands. They are desirable houseplants, as well. Several species of moth larvae eat exclusively from this plant, depending on it for their survival(FEIS Biological Archive, www.fs.fed.us/database/feis, Oct. 19, 1998).
The final carnivorous plant is the Dionaea muscipalia, or, as it is commonly known, the Venus Flytrap(www.flytrap.demon.cc.uk/plant.html). This plant is used as a household plant not only for its looks, but also for its gruesomely effective mode of decreasing the fly population in one’s home.
This plant, contrary to rumors, does not eat humans; in fact, the largest organisms reported eaten by these creatures are frogs and mice, and these are usually deathly ill or wounded at the time of ingestion. This plant lives in North and South Carolina. It is not edible, but plays a role in the environment, as all plants and animals do(Watson, L., and Dallwitz, M.J.(1992). The Families of Flowering Plants: Descriptions, Illustrations, Identification, and Information Retrieval. New York: Del Ray).
So, in conclusion, carnivorous plants are integral to their ecosystems, and these ecosystems in turn are necessary for the health of the planet and mankind. Without carnivorous plants, these systems could not properly function and life would not be as it is today.