Dionaea muscipula - Venus Flytrap / Dionea / Dionéia / Vênus Papa-Moscas (Soland. ex Ellis)
Plantae: Magnoliopsida: Caryophyllales: Polygonineae: Droseraceae
Date: 2nd of May, 2018 at 08:52:30pm.
Location: Brazil, Ceará, Fortaleza.
Dionaea muscipula is the sole species within the genus Dionaea, with no subspecies, and belongs in the class Magnoliopsida, order Caryophyllales, suborder Polygonineae and family Droseraceae. The common name "Venus flytrap" comes from the Roman goddess of love and fertility.
They are carnivorous plants (correct term as they can eat small Amphibia, spiders and insects) that produce leaves with a trap distally from the central bulb. This trap grows slowly with no visible openings, proceeding to open as it matures and visually look like a mouth. This trap mechanism is an evolved defence against herbivory while also acting as a nutrient provider to the plant, that usually grows in poor soil. The traps are required to be elastic and turgid to work properly.
There are tiny setae within the trap that need to be stimulated to send a signal consisting of calcium (Ca, atomic number 20) ions to the cells between the lobes and the fulcrum. The lobes' external layer of cells is able to secrete protons in the cell's wall, loosing them up and allowing them to fill up rapidly through osmosis. This is one of the explanations given to the exact mechanism that makes the traps shut, and is still target of speculation. Another theory is that the internal wall of the trap can secrete other ions, allowing the water to leave, making the cells collapse. Both of these can be correct or partially correct, wrong, or only one of these is correct or partially correct. It is known, though, that the trigger setae have an important role in this. At least two setae need to be triggered at the same time for the trapping to occur; this avoids that a simple rainwater drop triggers the mechanism in vain. When an insect gets inside the trap and triggers it to shut, the constant movements of the insect trying to escape will keep stimulating the trigger setae. This makes the traps' trapping mechanism stronger which will allow the plant to digest the prey. If there are no stimuli to the setae within a shut trap, the plant will understand that there is nothing inside or that what triggered the setae was probably water, an already dead insect or other materials and will open to avoid using up more energy to digest something not worthwhile. The shutting process takes away a lot of energy from the plant; if it shuts without recovering the energy lost by digesting an insect, the trap is more likely to wilt and die. Digestion occurs through enzymes secreted in the lobes and can vary in duration, reaching up to 10 days, maybe more. Once the digestion is finished, the trap will reopen and an exoskeleton will be left inside, with no need to be removed.
Dionaea muscipula do not need to feed to live. They can live with water and sunlight alone really well, assuming the substract and care are adequate; the plant can capture prey on its own and, even though it does not need to feed, the plant will become more flashy if it captures prey. The ideal substracts are those that are poor in nutrients due to the plant's sensitive roots. The roots are mainly there to absorb water; a substract with a medium quantity of nutrients or many nutrients will burn the roots and the plant will most likely die. They are usually sold in floricultures in litter substracts, which require more water than usual, but still works. A good substract can include a mixture of poor quality sand and Sphagnum sp. (Sphagnidae: Sphagnales: Sphagnaceae) (L.) moss, but they can live really well in Sphagnum sp. moss alone, as is the situation of the subject portrayed. An alternative substract includes a mixture of poor quality sand and peat. The substract's pH must be between 3.0 and 4.5.
Dionaea muscipula need abundant sunlight and abundant water to live. Too much sunlight with too little water will harm the plant as will too much water with too little sunlight. The water must not contain chlorine (Cl, atomic number 17) as this element is toxic to the plant. Filtered, distilled or rain water is recommended. The substract must never be allowed to dry, and you can water them many times a day if needed, always making sure there's a balance between water and sunlight and that they receive abundant sunlight.
Due to their natural habitats, Dionaea muscipula can live for several weeks underwater. These include swamps and bogs with poor nitrogen and, besides the defensive mechanism against herbivory, it is one of the main reasons that caused the evolution in the plant to be able to capture nitrogen-rich prey, providing them with what the soil lacks.
A floral stem might develop during spring, but is not a rule, proceeding to form small, white flowers. They can produce many floral stems at a time. During the development of the floral stems, it is natural that the plant will look less flashy as the stem's growth requires a great amount of energy to be used. The growth of the stem can sometimes kill a weakened plant. If the plant is undergoing a process of recovery and a stem begins to grow, it is recommended to cut it off to avoid the energy loss. Mechanical pollination (also called "hand polination") with the use of a swab can be done; by rubbing it on the polen of the stamen and then rubbing the polen-full swab on the pistil of the flower, there is a higher probability ratio for it to produce seeds, especially if done daily. The flowers are usually hermaphordites. This pollination method is mostly done due to the lack of natural pollinators within their introduced range. The seeds are small, black, shiny and water drop-shaped; simply leaving them ON the wet substract will most likely grow more plants. The seeds need to receive sunlight, so when watering the substract, avoid strong water jets that might bury the seeds. The seeds can take a very long time to germinate.
They MIGHT undergo a dormancy period in winter, when the plant will usually wilt, look black and dead, but this is not a rule. The central hibernacula (a little bud-like structure), though, is alive and the plant will resume growth in spring. During dormancy, resistance to cold is drastically increased. Achieving dormancy might be problematic in tropical areas due to the lack of the supposedly needed cold for the mechanism to activate. Starting in autumn it is, doubtfully, recommended by some people to place the plant in a fridge to induce the dormancy. Some people do not recommend this due to the great risk of rot and prefer to let the natural cycle roll out. In nature, during dormancy, the plant is usually covered in snow, so the lack of sunlight in this period might not be problematic, but I have no sources confirming this. Furthermore, when the plant gets used to the weather, colder days even under tropical zones might trigger the dormancy mechanism, as noted by various friends. Also, the dormancy seems to happen a lot during the summer as well (numerous reports on this from my friends), which suggests that what triggers the dormancy might not be entirely connected to the cold and further studies would be required. Dormancy is vital to drastically increase their longevity, but some plants are able to live a relatively long time even without the dormancy period.
Dionea (Raf.), spelling variant.
Dionaea corymbosa ((Raf.) Steud. (1840))
Dionaea crinita (Sol. (1990)) as synonym.
Dionaea dentata (D'Amato (1998)) name published without description.
Dionaea heterodoxa (D'Amato (1998)) nom.nud.
Dionaea muscicapa (St.Hil. (1824)) sphalm.typogr.
Dionaea sensitiva (Salisb. (1796))
Dionaea sessiliflora (Raf.) Steud. (1840)
Dionaea uniflora (Raf.) Steud. (1840)
Drosera corymbosa (Raf. (1833))
Drosera sessiliflora (Raf. (1833))
Drosera uniflora (Raf. (1833))
There are many variations of Dionaea muscipula. You can check the variations here: https://en.wikipedia.org/wiki/List_of_Venus_flytrap_cultivars
And here: http://cpphotofinder.com/Dionaea.html
There is a proposed evolutionary history theory to these plants and Drosera inferred through phylogenetic studies, in which it was proposed that they evolved due to five main factors:
1 - Large insects could break free from sticky glands alone, requiring a method of trapping prey reliably and adequately to avoid kleptoparasitism and to provide them with a better means of digestion.
2 - Evolutionary pressure selected plants with shorter response times.
3 - The more active the trap became, more energy was required to shut up on prey. Plants that could somehow differentiate insects from random matter or rain drops had an advantage, explaining the specialization of the inner tentacles into trigger hairs.
4 - Due to the reliance on closing around prey, the tentacles of a Drosera sp. would lose their original function, turning into the "teeth" and trigger hairs. This is an example of natural selection that utilizes pre-existing structures for new functions.
5 - Digestive glands were developed inside the trap instead of using the dews in the stalks, differentiating them from Drosera.
Certainly, other evolutionary factors included their distribution status in which the nutrient-poor soils were a barrier to the plants and feeding would allow them to acquire those nutrients, as well as at the same time protect them from herbivory.
interesting curiosities on Caryophyllales: https://www.worldwidefruits.com/order-caryphyllales.html
International Carnivorous Plants Society: http://legacy.carnivorousplants.org/cpn/samples/v27n1p27_28.html
Integration of trap‐ and root‐derived nitrogen nutrition of carnivorous Dionaea muscipula: https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.13120
The Venus flytrap , ''Dionaea muscipula'', is a carnivorous plant native to subtropical wetlands on the East Coast of the United States. It catches its prey—chiefly insects and arachnids— with a trapping structure formed by the terminal portion of each of the plant's leaves and is triggered by tiny hairs on their inner surfaces. When an insect or spider crawling along the leaves contacts a hair, the trap closes if a different hair is contacted within twenty seconds of the first strike. The requirement.. more