Venus flytrap

The plant's common name (originally "Venus's flytrap") refers to Venus, the Roman goddess of love, beauty, desire, sex, fertility, prosperity, victory, and women. The genus name, Dionaea ("daughter of Dione"), refers to an epithet of the Greek goddess Aphrodite, while the species name, muscipula, is Latin for both "mousetrap" and "flytrap". The term is similar to the term tippet-de-witchet which derives from tippet (a wrapping piece of clothing) and witchet (archaic term for vagina). In contrast, the English botanist John Ellis, who gave the plant its scientific name in 1768, wrote that the plant name tippitywichit was an indigenous word from either Cherokee or Catawba. ==Discovery by Europeans==

On 2 April 1759, the North Carolina colonial governor, Arthur Dobbs, penned the first written description of the plant in a letter to English botanist Peter Collinson. In the letter he wrote: "We have a kind of Catch Fly Sensitive which closes upon anything that touches it. It grows in Latitude 34 but not in 35. I will try to save the seed here." A year later, Dobbs went into greater detail about the plant in a letter to Collinson dated Brunswick, 24 January 1760. This was the first detailed recorded notice of the plant by Europeans. The description was before John Ellis's letter to The London Magazine on 1 September 1768, and his letter to Carl Linnaeus on 23 September 1768, in which he described the plant and proposed its English name ''Venus's Flytrap and scientific name Dionaea muscipula''. == Description ==

The Venus flytrap is a small plant whose structure can be described as a rosette of four to seven leaves, which arise from a short subterranean stem that is actually a bulb-like object. Each stem reaches a maximum size of about three to ten centimeters, depending on the time of year; longer leaves with robust traps are usually formed after flowering. Flytraps that have more than seven leaves are colonies formed by rosettes that have divided beneath the ground. '' by William Curtis (1746–1799) Fly trap leaves The leaf blade is divided into two regions: a flat, heart-shaped photosynthesis-capable petiole, and a pair of terminal lobes hinged at the midrib, forming the trap which is the true leaf. The upper surface of these lobes contains red anthocyanin pigments and its edges secrete mucilage. The lobes exhibit rapid plant movements, snapping shut when stimulated by prey. The trapping mechanism is tripped when prey contacts one of the three hair-like trichomes that are found on the upper surface of each of the lobes. The mechanism is so highly specialized that it can distinguish between living prey and non-prey stimuli, such as falling raindrops; two trigger hairs must be touched in succession within 20 seconds of each other or one hair touched twice in rapid succession, The edges of the lobes are fringed by stiff hair-like protrusions or cilia, which mesh together and prevent large prey from escaping. These protrusions, and the trigger hairs (also known as sensitive hairs) are likely homologous with the tentacles found in this plant's close relatives, the sundews. Scientists have concluded that the snap trap evolved from a fly-paper trap similar to that of Drosera. The holes in the meshwork allow small prey to escape, presumably because the benefit that would be obtained from them would be less than the cost of digesting them. If the prey is too small and escapes, the trap will usually reopen within 12 hours. If the prey moves around in the trap, it tightens and digestion begins more quickly. Speed of closing can vary depending on the amount of humidity, light, size of prey, and general growing conditions. The speed with which traps close can be used as an indicator of a plant's general health. Venus flytraps are not as humidity-dependent as are some other carnivorous plants, such as Nepenthes, Cephalotus, most Heliamphora, and some Drosera. The Venus flytrap exhibits variations in petiole shape and length and whether the leaf lies flat on the ground or extends up at an angle of about 40–60 degrees. The four major forms are: 'typica', the most common, with broad decumbent petioles; 'erecta', with leaves at a 45-degree angle; 'linearis', with narrow petioles and leaves at 45 degrees; and 'filiformis', with extremely narrow or linear petioles. Except for 'filiformis', all of these can be stages in leaf production of any plant depending on season (decumbent in summer versus short versus semi-erect in spring), length of photoperiod (long petioles in spring versus short in summer), and intensity of light (wide petioles in low light intensity versus narrow in brighter light). Other parts The plant also has a flower on top of a long stem, about long. The flower is pollinated from various flying insects such as sweat bees, longhorn beetles and checkered beetles. ==Habitat and distribution==

Habitat The Venus flytrap is found in nitrogen- and phosphorus-poor environments, such as bogs, wet savannahs, and canebrakes. Small in stature and slow-growing, the Venus flytrap tolerates fire well and depends on periodic burning to suppress its competition. Fire suppression threatens its future in the wild. It survives in wet sandy and peaty soils. Although it has been successfully transplanted and grown in many locales around the world, it is native only to the coastal bogs of North and South Carolina in the United States, specifically within a radius of Wilmington, North Carolina. One such place is North Carolina's Green Swamp. There also appears to be a naturalized population of Venus flytraps in northern Florida as well as an introduced population in western Washington. The nutritional poverty of the soil is the reason it relies on such elaborate traps: insect prey provide the nitrogen for protein formation that the soil cannot. They tolerate mild winters, and require a period of winter dormancy to survive freezing temperatures and low photoperiods. Most professional carnivorous plant growers recommend dormancy, and Venus fly traps grown without dormancy may require more light, water, and food to remain healthy. They are full sun plants, usually found only in areas with less than 10% canopy cover. The habitats where it thrives are typically either too nutrient-poor for many noncarnivorous plants to survive, or frequently disturbed by fires which regularly clear vegetation and prevent a shady overstory from developing. It can be found living alongside herbaceous plants, grasses, sphagnum, and fire-dependent Arundinaria bamboos. Regular fire disturbance is an important part of its habitat, required every 3–5 years in most places for D. muscipula to thrive. After fire, D. muscipula seeds germinate well in ash and sandy soil, with seedlings growing well in the open post-fire conditions. The seeds germinate immediately without a dormant period. As of 2019, it was considered extirpated in North Carolina in the inland counties of Moore, Robeson, and Lenoir, as well as the South Carolina coastal counties of Charleston and Georgetown. Remaining extant populations exist in North Carolina in Beaufort, Craven, Pamlico, Carteret, Jones, Onslow, Duplin, Pender, New Hanover, Brunswick, Columbus, Bladen, Sampson, Cumberland, and Hoke counties, and in South Carolina in Horry county. Population A large-scale survey in 2019, conducted by the North Carolina Natural Heritage Program, counted a total of 163,951 individual Venus flytraps in North Carolina and 4,876 in South Carolina, estimating a total of 302,000 individuals remaining in the wild in its native range. This represents a reduction of more than 93% from a 1979 estimate of approximately 4,500,000 individuals. A 1958 study found 259 confirmed extant or historic sites. As of 2016, there were 71 known sites where the plant could be found in the wild. Of these 71 sites, only 20 were classified as having excellent or good long-term viability. ==Carnivory==

Prey selectivity ) Most carnivorous plants selectively feed on specific prey. This selection is due to the available prey and the type of trap used by the organism. With the Venus flytrap, prey is limited to beetles, spiders and other crawling arthropods. The Dionaea diet is 33% ants, 30% spiders, 10% beetles, and 10% grasshoppers, with fewer than 5% flying insects. Given that Dionaea evolved from an ancestral form of Drosera (carnivorous plants that use a sticky trap instead of a snap trap) the reason for this evolutionary branching becomes clear. Drosera consume smaller, aerial insects, whereas Dionaea consume larger terrestrial bugs. Dionaea are able to extract more nutrients from these larger bugs. This gives Dionaea an evolutionary advantage over their ancestral sticky trap form. Mechanism of trapping '' It is hypothesized that there is a threshold of ion buildup for the Venus flytrap to react to stimulation. The acid growth theory states that individual cells in the outer layers of the lobes and midrib rapidly move 1H+ (hydrogen ions) into their cell walls, lowering the pH and loosening the extracellular components, which allows them to swell rapidly by osmosis, thus elongating and changing the shape of the trap lobe. Alternatively, cells in the inner layers of the lobes and midrib may rapidly secrete other ions, allowing water to follow by osmosis, and the cells to collapse. Both of these mechanisms may play a role and have some experimental evidence to support them. Flytraps show an example of memory in plants; the plant knows if one of its trigger hairs have been touched, and remembers this for a few seconds. If a second touch occurs during that time frame, the flytrap closes. After closing, the flytrap counts additional stimulations of the trigger hairs, to five total, to start the production of digesting enzymes. '' Digestion If the prey is unable to escape, it will continue to stimulate the inner surface of the lobes, and this causes a further growth response that forces the edges of the lobes together, eventually sealing the trap hermetically and forming a "stomach" in which digestion occurs. Release of the digestive enzymes is controlled by the hormone jasmonic acid, the same hormone that triggers the release of toxins as an anti-herbivore defense mechanism in non-carnivorous plants. (See Evolution below) Once the digestive glands in the leaf lobes have been activated, digestion is catalysed by hydrolase enzymes secreted by the glands. One of these enzymes includes GH18 chitinase, which breaks down chitin-containing exoskeleton of trapped insects. Synthesis of this enzyme begins with at least five action potentials, which will stimulate transcription of chitinase. Oxidative protein modification is likely to be a pre-digestive mechanism used by Dionaea muscipula. Aqueous leaf extracts have been found to contain quinones such as the naphthoquinone plumbagin that couples to different NADH-dependent diaphorases to produce superoxide and hydrogen peroxide upon autoxidation. Such oxidative modification could rupture animal cell membranes. Plumbagin is known to induce apoptosis, associated with the regulation of the Bcl-2 family of proteins. When the Dionaea extracts were pre-incubated with diaphorases and NADH in the presence of serum albumin (SA), subsequent tryptic digestion of SA was facilitated. ==Evolution==

'', with short, wide, sticky leaf traps Carnivory in plants is a very specialized form of foliar feeding, and is an adaptation found in several plants that grow in nutrient-poor soil. Carnivorous traps were naturally selected to allow these organisms to compensate for the nutrient deficiencies of their harsh environments and compensate for the reduced photosynthetic benefit. Phylogenetic studies have shown that carnivory in plants is a common adaptation in habitats with abundant sunlight and water but scarce nutrients. The "snap trap" mechanism characteristic of Dionaea is shared with only one other carnivorous plant genus, Aldrovanda. For most of the 20th century, this relationship was thought to be coincidental, more precisely an example of convergent evolution. Some phylogenetic studies even suggested that the closest living relatives of Aldrovanda were the sundews. A 2009 study In many non-carnivorous plants, jasmonic acid serves as a signaling molecule for the activation of defense mechanisms, such as the production of hydrolases, which can destroy chitin and other molecular components of insect and microbial pests. In the Venus flytrap, this same molecule has been found to be responsible for the activation of the plant's digestive glands. A few hours after the capture of prey, another set of genes is activated inside the glands, the same set of genes that is active in the roots of other plants, allowing them to absorb nutrients. The use of similar biological pathways in the traps as non-carnivorous plants use for other purposes indicates that somewhere in its evolutionary history, the Venus flytrap repurposed these genes to facilitate carnivory. Proposed evolutionary history Carnivorous plants are generally herbaceous, and their traps the result of primary growth. They generally do not form readily fossilizable structures such as thick bark or wood. As a result, there is no fossil evidence of the steps that might link Dionaea and Aldrovanda, or either genus with their common ancestor, Drosera. Nevertheless, it is possible to infer an evolutionary history based on phylogenetic studies of both genera. Researchers have proposed a series of steps that would ultimately result in the complex snap-trap mechanism: and are more likely to break free from sticky glands alone. Therefore, a plant with wider leaves, like Drosera falconeri, must have adapted to move the trap and its stalks in directions that maximized its chance of capturing and retaining such prey—in this particular case, longitudinally. Once adequately "wrapped", escape would be more difficult. ==Cultivation==

Plants can be propagated by seed, taking around four to five years to reach maturity. More commonly, they are propagated by clonal division in spring or summer. Venus flytraps can also be propagated in vitro using plant tissue culture. Most Venus flytraps found for sale in nurseries garden centers have been produced using this method, as this is the most cost-effective way to propagate them on a large scale. Regardless of the propagation method used, the plants will live for 20 to 30 years if cultivated in the right conditions. Cultivars Venus flytraps are by far the most commonly recognized and cultivated carnivorous plant, and they are frequently sold as houseplants. Various cultivars (cultivated varieties) have come into the market through tissue culture of selected genetic mutations, and these plants are raised in large quantities for commercial markets. The cultivars 'Akai Ryu' and 'South West Giant' have gained the Royal Horticultural Society's Award of Garden Merit. ==Conservation==

Although widely cultivated for sale as a houseplant, D. muscipula has suffered a significant decline in its population in the wild. The population in its native range is estimated to have decreased 93% since 1979. Status The species is under Endangered Species Act review by the U.S. Fish & Wildlife Service. The current review commenced in 2018, after an initial "90-day" review found that action may be warranted. A previous review in 1993 resulted in a determination that the plant was a "Potential candidate without sufficient data on vulnerability". The IUCN Red List classifies the species as "vulnerable". The State of North Carolina lists Dionaea muscipula as a species of "Special Concern–Vulnerable". The species is protected under Appendix II of the Convention on International Trade in Endangered Species (CITES) meaning international trade (including in parts and derivatives) is regulated by the CITES permitting system. NatureServe classified it as "Imperiled" (G2) in a 2018 review. The U.S. Fish and Wildlife Service has not indicated a timeline to conclude its current review of Dionaea muscipula. The Endangered Species Act specifies a two-year timeline for a species review. However, the species listing process takes 12.1 years on average. Threats The Venus flytrap is only found in the wild in a very particular set of conditions, requiring flat land with moist, acidic, nutrient-poor soils that receive full sun and burn frequently in forest fires, and is therefore sensitive to many types of disturbance. Habitat loss is a major threat to the species. The human population of the coastal Carolinas is rapidly expanding. For example, Brunswick County, North Carolina, which has the largest number of Venus flytrap populations, has seen a 27% increase in its human population from 2010 to 2018. As the population grows, residential and commercial development and road building directly eliminate flytrap habitat, while site preparation that entails ditching and draining can dry out soil in surrounding areas, destroying the viability of the species. D. muscipula requires fire every 3–5 years, and best thrives with annual brush fires. Although flytraps and their seeds are typically killed alongside their competition in fires, seeds from flytraps adjacent to the burnt zone propagate quickly in the ash and full sun conditions that occur after a fire disturbance. Because the mature plants and new seedlings are typically destroyed in the regular fires that are necessary to maintain their habitat, D. muscipula's survival relies upon adequate seed production and dispersal from outside the burnt patches back into the burnt habitat, requiring a critical mass of populations, and exposing the success of any one population to metapopulation dynamics. These dynamics make small, isolated populations particularly vulnerable to extirpation, for if there are no mature plants adjacent to the fire zone, there is no source of seeds post-fire. In 2014, the state of North Carolina made Venus flytrap poaching a felony. Since then, several poachers have been charged, with one man receiving 17 months in prison for poaching 970 Venus flytraps, and another man charged with 73 felony counts in 2019. Poachers may do greater harm to the wild populations than a simple count of individuals taken would indicate, as they may selectively harvest the largest plants at a site, which have more flowers and fruit and therefore generate more seeds than smaller plants. Additionally, the species is particularly vulnerable to catastrophic climate events. Most Venus flytrap sites are only above sea level and are located in a region prone to hurricanes, making storm surges and rising sea levels a long-term threat. == Designations ==

In 2005, the Venus flytrap was designated as the state carnivorous plant of North Carolina. ==In alternative medicine==

Venus flytrap extract is available on the market as an herbal remedy, sometimes as the prime ingredient of a patent medicine named "Carnivora". According to the American Cancer Society, these products are promoted in alternative medicine as a treatment for a variety of human ailments, including HIV, Crohn's disease and skin cancer, even though available scientific evidence does not support these health claims. ==See also==