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The Venus flytrap ( Dionaea muscipula) is a carnivorous plant native to the temperate and subtropical of North Carolina and South Carolina, on the East Coast of the United States. Although various modern hybrids have been created in Horticulture, D. muscipula is the only species of the monotypic genus Dionaea. It is closely related to the waterwheel plant ( Aldrovanda vesiculosa) and the cosmopolitan sundews ( Drosera), all of which belong to the family Droseraceae. (2025). 9780198779841, Oxford University Press. ISBN 9780198779841 Dionaea catches its prey—chiefly and —with a "jaw"-like clamping structure, which is formed by the terminal portion of each of the plant's leaves; when an insect makes contact with the open leaves, vibrations from the prey's movements ultimately trigger the "jaws" to shut via tiny hairs (called "trigger hairs" or "sensitive hairs") on their inner surfaces. Additionally, when an insect or spider touches one of these hairs, the trap prepares to close, only fully enclosing the prey if a second hair is contacted within (approximately) twenty seconds of the first contact. Triggers may occur as quickly as of a second from initial contact.
The requirement of repeated, seemingly redundant triggering in this mechanism serves as a safeguard against energy loss and to avoid trapping objects with no nutritional value; the plant will only begin digestion after five more stimuli are activated, ensuring that it has caught a live prey animal worthy of consumption. These hairs also possess a heat sensor. A forest fire, for example, causes them to snap shut, making the plant more resilient to periods of summer fires.
Although widely cultivated for sale, the population of the Venus flytrap has been rapidly declining in its native range. As of 2017, the species was under Endangered Species Act review by the U.S. Fish & Wildlife Service.
Historically, the plant was also known by the slang term "tipitiwitchet" or "tippity twitchet", possibly an oblique reference to the plant's resemblance to human female genitalia. The term is similar to the term tippet-de-witchet which derives from tippet 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 people. The plant name according to the Handbook of American Indians derives from the Renape word titipiwitshik ("they (leaves) which wind around (or involve)").
This was the first detailed recorded notice of the plant by Europeans. The description was before John Ellis' 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. Directions for Bringing over Seeds and Plants, from the East Indies and Other Distant Countries, in a State of Vegetation: Together with a Catalogue of Such Foreign Plants as Are Worthy of Being Encouraged in Our American Colonies, for the Purposes of Medicine, Agriculture, and Commerce. To Which is Added, the Figure and Botanical Description of a New Sensitive Plant, Called Dionæa muscipula: or, Venus's Fly-trap – (London, printed and sold by L. Davis, 1770).
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).
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.
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.
The mechanism by which the trap snaps shut involves a complex interaction between elasticity, turgor and growth. The trap only shuts when there have been Plant arithmetic of the trigger hairs; this is to avoid inadvertent triggering of the mechanism by dust and other wind-borne debris. In the open, untripped state, the lobes are (bent outwards), but in the closed state, the lobes are (forming a cavity). It is the rapid flipping of this bistability state that closes the trap, but the mechanism by which this occurs is still poorly understood. When the trigger hairs are stimulated, an action potential (mostly involving calcium ions—see calcium in biology) is generated, which propagates across the lobes and stimulates cells in the lobes and in the midrib between them.
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 proton () 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 , 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.Williams, S. E. 2002. Comparative physiology of the Droseraceae sensu stricto – How do tentacles bend and traps close? Proceedings of the 4th International Carnivorous Plant Society Conference. Tokyo, Japan. pp. 77–81.
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. (2025). 9780374533885, Scientific American / Farrar, Straus and Giroux. ISBN 9780374533885 After closing, the flytrap Plant arithmetic additional stimulations of the trigger hairs, to five total, to start the production of digesting enzymes.
Oxidative protein modification is likely to be a pre-digestive mechanism used by Dionaea muscipula. Aqueous leaf extracts have been found to contain 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 Trypsin digestion of SA was facilitated. Since the Exocrine gland of Droseraceae contain and possibly other degradative enzymes, it may be that the presence of oxygen-activating redox cofactors function as extracellular Saliva to render membrane-bound proteins of the prey () more susceptible to Proteolysis attacks.
Digestion takes about ten days, after which the prey is reduced to a husk of chitin. The trap then reopens, and is ready for reuse.
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 . It was not until 2002 that a molecular evolutionary study, by analyzing combined nuclear DNA and chloroplast DNA sequences, indicated that Dionaea and Aldrovanda were closely related and that the snap trap mechanism evolved only once in a common ancestor of the two genera.
A 2009 study presented evidence for the evolution of snap traps of Dionaea and Aldrovanda from a flypaper trap like Drosera regia, based on molecular data. The molecular and physiological data imply that Dionaea and Aldrovanda snap traps evolved from the flypaper traps of a common ancestor with Drosera. Pre-adaptations to the evolution of snap traps were identified in several species of Drosera, such as rapid leaf and tentacle movement. The model proposes that plant carnivory by snap trap evolved from the flypaper traps, driven by increasing prey size. Bigger prey provides greater nutritional value, but large insects can easily escape the sticky mucilage of flypaper traps; the evolution of snap traps would therefore prevent escape and kleptoparasitism (theft of prey captured by the plant before it can derive benefit from it), and would also permit a more complete digestion.
In 2016, a study of the expression of genes in the plant's leaves as they captured and digested prey was published in the journal, Genome Research. The gene activation observed in the leaves of the plants gives support to the hypothesis that the carnivorous mechanisms present in the flytrap are a specially adapted version of mechanisms used by non-carnivorous plants to defend against herbivorous insects. 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.
Phylogenetic studies using molecular characters place the emergence of carnivory in the ancestors of Dionaea muscipula to 85.6 million years ago, and the development of the snap-trap in the ancestors of Dionaea and its sister genus Aldrovanda to approximately 48 million years ago.
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.
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. Additionally, increased recreational use of natural areas in populated areas directly destroys the plants by crushing or uprooting them.
Fire suppression is another threat to the Venus flytrap. In the absence of regular fires, shrubs and trees encroach, outcompeting the species and leading to local extirpations. 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. 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.
Poaching has been another cause of population decline. Harvesting Venus flytraps on public land became illegal in North Carolina in 1958, and since then a legal cultivation industry has formed, growing tens of thousands of flytraps in commercial for sale as household plants. Yet in 2016, the New York Times reported that demand for wild plants still exists, which "has led to a 'Venus flytrap crime ring. 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.
Evolution
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. Carnivory has evolved independently six times in the angiosperms based on extant species, with likely many more carnivorous plant lineages now extinct.
Proposed evolutionary history
Carnivorous plants are generally Herbaceous plant, 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:
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 (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.
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. A 2011 review identified five categories of threats for the species: agriculture, road-building, biological resource use (poaching and lumber activities), natural systems modifications (drainage and fire suppression), and pollution (fertilizer).
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.
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