| Taxonomic Hierarchy | |
| Kingdom | Animalia – Animal, animals |
| Phylum | Mollusca – molluscs, mollusks |
| Class | Gastropoda Cuvier, 1797 – gastropods, slugs, snails |
| Order | Neotaenioglossa |
| Family | Pleuroceridae |
| Genus | Io I. Lea, 1831 |
| Species | Io fluvialis (Say, 1825) – spiny riversnail |
Venus Flytrap, also known as Venus's Flytrap
The Venus Flytrap is among a group of plants known as Carnivorous plants. There are various types of carnivorous plants, including flowering plants and fungi which prey and feed upon small animals and insects. Such species are sometimes referred to as insectivorous plants.
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Governor Arthur Dobbs of North Carolina was the first person to describe the plant. He named it "Fly Trap Sensitive". In 1760 he communicated about the discovery of the plant's peculiar ability to close and trap objects, to Mr. P. Collinson of England. Later, Mr. J. Bartram of Philadelphia sent specimens known to him as "Tipitiwitchet," to Mr. P. Collinson. The species was first described among the scientific community in 1768 by the American botanist J. Ellis in letters to Linnaeus providing a substantial description of the structure and functions of the leaves, suggesting even the insectivorous nature of the species. Linnaeus declared it the most wonderful of plants, Miraculum Naturae. Linnaeus presumed the plant exhibited extreme sensitivity, in which insects were accidentally captured and subsequently allowed to escape.
"But the plant, of which I now enclose you an exact figure, with a specimen of its leaves and blossoms, shews, that nature may have some view towards nourishment, in forming the upper joint of the leaf like a machine to catch food: upon the middle of this lies the bait for the unhappy insect that becomes its prey. Many minute red glands, cover its inner surface, and which perhaps discharge sweet liquor, tempt the poor animal to taste them; and the instant these tender parts are irritated by its feet, the two lobes rise up, grasp it fast, lock the row of spines together and squeeze it to death. And, further, lest the strong efforts for life, in the creature thus taken, should serve to disengage it, three small erect spines are fixed near the middle of each lobe, among the glands, that effectually put an end to all its struggles. Nor do the lobes ever open again, while the dead animal continues there."
The letter which contained inaccuracies did not convince Linnaeus of the plant's carnivorous nature, he believed rather, that the insects were released, and trapped merely due to oversensitivity, being such the case with Mimosa pudica.
Ellis arrived at incorrect conclusions about the functions in the plant, including the three erect spines which were later discovered to be trigger hairs on the inner surface of the trap, and a view shared by Erasmus Darwin, botanist and grandfather of Charles Darwin, who wrote,
"In the Dionaea muscipula there is a still more wonderful contrivance to prevent the depredations of insects: the leaves are armed with long teeth, like the antennae of insects, and lie spread upon the ground around the stem, and are so irritable, that when an insect creeps upon them they fold up and crush or pierce it to death."
However the insectivorous nature of the plant was more elaborately investigated by Charles Darwin and described in his book, Insectivorous Plants (1875).
Charles Darwin observed the plant during its digestive state, noting the abundance of the secreted fluid. Making a small opening at the base of one lobe which contained a large crushed fly, the secretion continued to run down the rootstalk a total of nine days, during which the plant was under steady observation.
The required time for digestion is approximately ten days to complete, after which the leaf reopens. Each leaf, or trap, can capture an average of three or four insects during its life span after which it ceases to function. Otherwise, when the trap has been triggered without successful capture of prey it can open and close many more times.
Ellis named the plant Dionaea. The origin of the name Dionaea has its origin in Greek and Roman mythology. In Greek, Dione is the mother of Aphrodite and at times used as an alternative name for the goddess of love. To the Romans, Venus was the goddess of love.
The Venus Flytrap is a native perennial found near the borders of coastal North and South Carolina around swampy bogs. Seldom ever does the flytrap survive well after relocation from its wet native habitat. Often flytraps are found in the presence of other carnivorous plants such as Sundews, Butterworts, Bladderworts and Pitcher Plants. The flytraps inhabit relatively level areas, and tend not to be found where depressions lie due to excess water. They thrive in damp soil, although it has been observed that during relatively dry periods there is no apparent harm to the plants.
Several methods are employed among carnivorous plants to trap their prey. Venus Flytrap's method is different from many other carnivorous plants and referred to as a "Mechanical Trap," specifically a "snap trap". Each leaf has two lobes, standing at rather less than a right angle to each other. The typical angle formed by the lobes is 40 to 50 degrees.
The upper surfaces are covered with minute circular sessile glands. The prey is trapped by rapid closure of the lobes around the insect when it touches one of the three sensory hairs, or fine-pointed bristles. In rare instances there may be as many as four trigger hairs on each surface. The trap has been compared to a hinge but this is inaccurate because a hinge has an articulated joint. The trap has none. It is equipped with bristles that are sometimes referred to as cilia. There are two types of glands,
This reaction, snapping shut and the leaf closing around the insect, occurs in about half a second in normal daytime temperatures. The spikes interlock, and the insect is trapped. After suitable prey is captured, within thirty minutes a narrowing phase begins in which the lobes become tightly pressed together and the outline of captured prey is visible while soft-bodied insects are crushed. This is followed by the release of digestive enzymes within the trap's interior whilst a protective seal is produced just below the marginal spines. If the insect has not been crushed by the lobes, it is likely the insect drowns in the digestive fluids.
The leaf then forms what may be referred to as a "temporary stomach" of sorts. With the insect imprisoned, the Flytrap's glands pour out a red acidic secretion or "sap" containing an enzyme that will dissolve the soft body parts. This digestive enzyme is similar to that which is produced by the leaves of the Sundew plant.
The Venus Flytrap grows from a bulb-like rootstalk and bears slender flower stalks which reach about a foot in height, producing a corymbs of white flowers which sprout in May and bloom in June. The stalk may bear between 1-15 white flowers. Each flower consists of 5 green sepals, 5 white petals, typically 15 stamens and 1 compound pistil. The leaves grow two to eight inches long and located at the base of the plant in a spreading rosette.
During the changing seasons the plant takes on varying characteristics. During the spring, leaves tend to be green with broad petioles which lateral extensions are referred to as "wings". Red coloration is limited or absent, if it is present, it is restricted to the glands on the inner surface of the traps. When late spring becomes summer, the spring leaves are terminated by flowering. When flowering has completed, the summer leaves are produced which are as long or longer, much more narrow and almost wingless. The summer leaves produce the largest traps which tend to grow vertically. With the onset of fall, winter-like leaves are produced which are the smallest. Frost may kill the leaves during the winter. Those which survive winter, tend to be prostrate and about the size of spring to summer leaves.
The bright red coloration in some flytraps seems to be influenced by its exposure to light. Though genetic factors play a role, flytraps thrive well in intense light with most of the plants developing the deep red maroon coloration in the traps, however, when there is insufficient lighting, the plants tend to develop with less healthy characteristics and remain a green pigmentation throughout. Although light contributes to their overall preferred health, direct sunlight is discouraged when cultivated in enclosed containers.
Venus Flytrap is the only known species in the genus Dionaea, therefore making it monotypical.
| Kingdom | Plantae – plants |
| Subkingdom | Viridaeplantae – green plants |
| Infrakingdom | Streptophyta – land plants |
| Division | Tracheophyta – vascular plants |
| Subdivision | Spermatophytina – seed plants |
| Infradivision | Angiospermae – flowering plants |
| Class | Magnoliopsida |
| Superorder | Caryophyllanae |
| Order | Caryophyllales |
| Family | Droseraceae – sundews |
| Genus | Dionaea (J. Ellis) – Venus flytrap, Venus fly trap |
| Species | Dionaea muscipula (J. Ellis) – Venus fly trap, Venus flytrap |
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Fabre, Jean Henri [fȧ′br’] (1823-1915), Famed French entomologist, born at Saint-Léons (Aveyron) France on December 21, 1823 of a humble peasant family. He became famous for his largely self-taught, study of insects and their life, histories, habits and instincts. His primary focus tended to be with bees, ants, beetles, grasshoppers and spiders. He was educated at normal schools in Rodez and Vaucluse, and later at the École Normale of Vauclause. At the age of 20 he commenced teaching at the school in Carpentras (1842). Later he taught physics and chemistry at the College of Ajaccio in Corsica (1843-1851), and at the Avignon Lycée (1853).
The teaching profession had paid poorly and having discovered a process for the production of madder-dye, hoped to achieve financial security by manufacturing the dye; but the simultaneous discovery of aniline dyes doomed his venture to fail.
In 1879 he retired to Sérignac, in Provence, where he at first earned his living by writing textbooks which were used in French schools and did well popularizing science. Fabre's real interest however, had always been natural history. He became interested in the habits and instincts of insects while he was studying for his doctorate. After his retirement from teaching in 1871, he lived in seclusion at Serignan, and devoted himself exclusively to the study of entomology, collecting and observing insects.
Fabre did important research on the orders Hymenoptera (wasps), Coleoptera (beetles), and Orthoptera (grasshoppers).
Fabre did not accept the conclusions of previous studies in this field and based all his research on direct observation of insects in their natural environments. In his study of the Hymenoptera, he found that wasps frequently sting their prey in the region of nerve centers, thus rendering them immobile. In this condition they may be stored for eating at a future time. Fabre believed that this specialized behavior demonstrated reasoning power, and he gradually came to the conclusion that habits are not fixed in insects, and that the theory of evolution is invalid.
Based on his observations of wasps paralysing their prey in specialized neuro-sensitive areas, he described the importance of inherited instinct as a behavior pattern in insects. In 1866, he isolated from the madder plant a coloring substance, which was identified as alizarin that later became useful in biological stain.
Along with his work on the relationship between the human and insect mind, Fabre also did research on the relationship of insects to agriculture. This latter work was stressed in his book Souvenirs Entomologiques (10 volumes, 1879-1907), parts of which have been translated to English and are among the most important works in the field of entomology. He became a corresponding member of the Institute of France, and a chevalier of the Legion of Honor. He also wrote La Science Élémentaire (1862), De Sciences Naturelles (1875) and La Vie des Insects (1910), The Life and Love of the Insect (1911), Social Life in the Insect World (1912), The Life of the Fly (1913), Bumble Bees (1915) and others. He was unsympathetic to the theory of evolution and opposed Charles Darwin's theory of evolution, considering the purposeful acts characteristic in insect behaviors, emphasizing those differences in contrast to the intelligent behavior of man, to give support of his anti-evolution beliefs. However, Charles Darwin admired his work and termed him the "incomparable observer." Fabre died at Sérignac on October 11, 1915.
 Long before he was old enough to go to school Jean Henri Fabre was interested in insects. He thought them more fun than other animals. In his old age he would sit still for hours watching an ant nest or a hive of bees working. His neighbors thought he was odd, but his patience paid off. By observing insects, he became famous later in life as an acclaimed scientist. Fabre was born in the French village of St. Leons. His family had very little money, but when he was old enough he sold lemons to earn money to go to school. He was such an extraordinary student that he was given a scholarship so that he could go to college. He finished college and began teaching science when he was only 19 years old. After nearly 30 years he gave up teaching so that he would have more time to study insects. He wrote many books about them, such as Our Humble Helpers and The Life of the Fly. No one gave Fabre's work much attention until he was nearly 80 years old. Then he was given great honor. A few years before he died the French government gave him a pension as a reward for what he had done to aid science. |
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Seeking ClarificationSource: Encyclopedia International, ©1966 (Grolier Inc.) Source: Funk and Wagnalls Encyclopedia, ©1950 |
