It is closely related to the waterwheel plant (Aldrovanda vesiculosa) and the cosmopolitan sundews (Drosera), all of which belong to the family Droseraceae.
[6] 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.
[11][17] The plant name according to the Handbook of American Indians derives from the Renape word titipiwitshik ("they (leaves) which wind around (or involve)").
[18][19] 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.
[26] 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;[27] longer leaves with robust traps are usually formed after flowering.
[29] The edges of the lobes are fringed by stiff hair-like protrusions or cilia, which mesh together and prevent large prey from escaping.
Speed of closing can vary depending on the amount of humidity, light, size of prey, and general growing conditions.
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.
Small in stature and slow-growing, the Venus flytrap tolerates fire well and depends on periodic burning to suppress its competition.
[8] 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.
After fire, D. muscipula seeds germinate well in ash and sandy soil, with seedlings growing well in the open post-fire conditions.
[48] 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.
[51] After closing, the flytrap counts additional stimulations of the trigger hairs, to five total, to start the production of digesting enzymes.
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.
[55] Since the secretory glands of Droseraceae contain proteases and possibly other degradative enzymes, it may be that the presence of oxygen-activating redox cofactors function as extracellular pre-digestive oxidants to render membrane-bound proteins of the prey (insects) more susceptible to proteolytic attacks.
[58] Phylogenetic studies have shown that carnivory in plants is a common adaptation in habitats with abundant sunlight and water but scarce nutrients.
[43] Carnivory has evolved independently six times in the angiosperms based on extant species, with likely many more carnivorous plant lineages now extinct.
[60] It was not until 2002 that a molecular evolutionary study, by analyzing combined nuclear 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.
[60][61] 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.
[53][63] 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.
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.
Researchers have proposed a series of steps that would ultimately result in the complex snap-trap mechanism:[60][61] 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.
[68] 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.
[77] 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.
[8] 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).
[79] 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.
[83] 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.
[88] Venus flytrap extract is available on the market as an herbal remedy, sometimes as the prime ingredient of a patent medicine named "Carnivora".