Potted fly traps are used in sunny windowsills and balconies to watch carnivorous plants known as nature.

Flytrap (perennial herb)

Flytrap, (Dionaea muscipula), whose English name is Venus Flytrap, is a perennial herb native to North America. It is a very interesting insectivorous plant. Its stem is very short. It has a shell-like trap at the top of the leaf and can secrete nectar. When a bug invades, it can be caught, digested and absorbed very quickly.

Because there are regular bristles on the edges of the leaves, it feels like Venus' eyelashes, meaning "Venus's fly trap". Chinese and Japanese also have the nickname "flies in hell" for flycatchers. Its main feature is that it can quickly close its leaves to prey on insects, which is the same carnivorous plant as its distant relative, pitcher plant, and is the only one of the genus flycatcher in the family Acanthaceae, which belongs to vascular plants. Potted plants can be used for sunny windowsills and balconies, and can also be specially used for planting trough cultivation. Flytrap is known as the carnivorous plant in nature. Flytrap has become the most beloved insectivorous plant in China because of its unique trapping ability and cool appearance.

Morphological characteristics

Flytrap (Catchfly), one of the vascular plants, is a popular insectivorous plant with complete roots, stems, leaves, flowers and seeds. Its leaf is the most important and obvious part, with the function of preying on insects, obvious spiny hairs and red sessile glands, which looks like a big mouth with teeth and claws. Potted plants can be used for sunny windowsills and balconies, and can also be used for planting trough culture. it is a perennial herb native to North America.

It is said that because there are regular bristles on the edges of the leaves, it feels like Venus' eyelashes, so the English name is Venus Flytrap, which is the only one in the genus Flycatcher of the family Euphorbiaceae, which is known as the natural carnivorous plant.

Flytrap is found only in the coastal plains of southeastern South Carolina and the northeastern corner of North Carolina.

However, the survival of the flytrap in its origin is threatened by human activities. The rapid increase in population has deprived the flytrap of its living space, and as a result of man-made intervention in the occurrence of natural wildfires, some small shrubs have begun to grow in these areas, thus blocking the sunlight of the flytrap. As a result, flytraps are being introduced into other areas for restoration, such as New Jersey and California. It has been successfully naturalized in Florida and has become a large ethnic group.

Leaf

The leaves of the flytrap (Venus Flytrap) grow from the central part and belong to whorls, showing sedentary growth in clumps. The central part that grows flat or linear like a wing is the part of the petiole, and the petiole of the native species is as flat as a leaf, f, because it looks like a leaf, so it is also called a false leaf.

There is an insect trap at the end of the petiole, which is the part of the leaf that catches insects. there are many sessile glands on the front, usually red or orange, and the fewer sessile glands the closer to the leaf green. this part is the part that secretes digestive juices to break down insects or absorb their nutrients. The leaf green has toothlike bristles, and the base of the bristles has secretory glands, which secrete mucus, which is used to prevent insects from breaking away and sticking to the leaves. This kind of leaf has the special function of catching insects, and the special appearance, it belongs to the "insect-trapping leaf" among the abnormal leaves.

Because new leaves are produced from the center, the outer layer of the leaf is older. New lateral buds are sometimes produced at the base of the outermost petiole. There are two types of petioles of the flytrap, some of which are slender, 7-16 cm long and extend toward the air, while others have short, chubby petioles that are laid flat on the surface. The inside of the trap usually shows red colors, most of which are pigments from the digestive glands, which can promote the production of plant pigments when the plant can receive sufficient sunlight, ranging from orange to reddish purple. Some artificial flytraps even produce pigments outside the digestive glands, thus turning the whole plant red.

Flowers

Flytraps (Venus Flytrap) bloom from early summer to midsummer, and flower stems grow in the early days. Each stem has about five to ten buds, belonging to the standard corymbose inflorescences, and white flowers bloom in sequence every day. In principle, each flower will produce only one flower stem, if the growth environment is suitable, if the nutrients are adequate, sometimes there will be two flower stems, normally five petals and five calyx, and occasionally six petal variants. There are about ten stamens, and there will be a pistil in the center with a bifurcated stigma.

The phenomenon of co-pollination of flytrap is less, because when the anther of stamen grows pollen, the style of pistil is closed. When the stamens begin to pour outward, the stigma will open and become bifurcated, which is in a state of possible pollination. This kind of stamen matures before the pistil grows, which is quite common in the plant kingdom, mainly to avoid pollination of the same plant. In general technical terms, this kind of flower is called "stamen premature flower" (Protandrous flower). In addition to the flower stem, there is generally no higher part of the upward growth, the normal stem is short and difficult to detect, and the petiole and leaves are not higher than the flower stem. This is a characteristic of insectivorous plants. Because in addition to preying on insects to absorb its nutrients, for the continuation of future generations also need the assistance of insects to pollinate, belonging to insect-pollinated flowers. Therefore, a distinction must be made between the supplementary leaves and the flowers, which can be said to be the natural wisdom given to them by nature.

Growing environment

Flytrap (Venus Flytrap) has the habit of preying on insects, which is generally called "carnivorous plant" (Carnivorous plant) or "insect-eating plant" (Insectivorous plant). As mentioned above, the predation organ of the flytrap is the part of its leaves. Most of these carnivorous plants grow in wetlands where nutrients are poor, and in order to supplement insufficient nutrients, especially nitrogen and phosphoric acid, they use specially evolved structures to prey on insects to digest their nutrients.

The original place of the flytrap belongs to the grassland on the wetland, and the soil in this area is mostly peat and silica sand. Most of its water source is Rain Water, because Rain Water fell to the earth through the fusion of atmosphere and carbon dioxide, resulting in an acidic environment, its pH value is about about pH5-6. From this, it can be known that the flytrap prefers places with sufficient water and acidic environment as the medium.

The acidic soil and the low temperature hinder the growth of bacteria that break down organic matter. While the organic matter is not decomposed, the remains of plants such as water moss can not be completely decomposed and decompose, and these corrupt organic matter will become peat, which is very lack of nutrients. In addition, after years of being washed away by Rain Water, trace elements have almost been lost. Therefore, in addition to the lack of nitrogen and phosphoric acid, which are necessary for growth, the original land of flytrap is a barren land that is also very deficient in trace elements.

Flytrap is a perennial herb. After the seed germinates and reaches the mature stage in 4 ~ 5 years, it can blossom and bear fruit. With good care, the flytrap can live for at least 20 to 30 years.

The flytrap begins to blossom soon after it grows new leaves in spring. It grows a flowering stem as high as 15 to 25 centimeters, with about 10 buds at the top. There is a white flower every other day. A flower can bloom for a few days before pollination, but if pollination is successful, the flower will die the next day, then the ovary will slowly expand, and the fruit will ripen about a few weeks later. Ripe fruit contains dozens of black, droplet-shaped seeds.

After flowering, it is also summer, and the flytrap will continue to grow more leaves and larger traps, which is the season when the flytrap needs a lot of predation to store nutrients for next year's flowering. The fruit that bears at the end of spring will mature in summer, and the seeds that burst will germinate after a period of time. The young flytrap first grows false leaves, then grows the first cotyledon with a complete trap and begins to catch insects.

The leaves of the flytrap live for about a few months (2-3 months) in autumn and only a few weeks in summer; the old leaves will gradually turn yellow, lose their ability to catch insects, and finally turn black and die, but the new leaves will continue to come out from the center; throughout summer, the flytrap will continue to grow new leaves until autumn, when another kind of leaf grows more slowly. At this time, the summer leaves are so big that they have withered, and the flytrap is ready for the winter. In winter, some very small traps will remain, but they have lost their ability to catch insects and can hardly be used; when the climate is too cold, the leaves on the ground will wither.

The predation structure of the flytrap is a clip formed by a left-right symmetrical leaf. The clip-like structure is specialized from the leaves, while the leaf-like structure connecting the trap is the petiole. The outer edge of the trap is lined with spiny hairs, which are soft and can be used to prevent captured insects from escaping. When the traps catch the insects, the hairs at both ends of the clips are crisscrossed and become a cage, making it impossible for the insects to escape.

The inside of the trap is red and covered with many tiny red dots, which are the digestive glands of the flytrap. Three pairs of fine hairs can be seen on the inside of the trap, which is the sensory hair of the flytrap, which is used to detect whether the insect is in a suitable position to catch. Most traps have only five pairs of sensory hairs, but they may also produce one or more sensory hairs.

Distribution range

Flytrap (Venus Flytrap) exists only in the coastal plains of southeastern South Carolina and the northeastern corner of North Carolina in the United States. In its native Carolina, flytrap grows in wet sandy or peat wetlands or swamps, which usually take the form of grasslands, with only sporadic pine trees, so they are open and can receive a lot of sunlight. The climate here is warm and humid, hot in summer, warm at night, and cold in winter, but not so cold that it often snows.

However, the survival of the flytrap in its origin is threatened by human activities. The rapid increase in population has deprived the flytrap of its living space, and as a result of man-made intervention in the occurrence of natural wildfires, some small shrubs have begun to grow in these areas, thus blocking the sunlight of the flytrap. As a result, flytraps are being introduced into other areas for restoration, such as New Jersey and California. However, it has been successfully naturalized in Florida and has become a large ethnic group.

Fly-catching grasslands are found along the east coast of North America, and their natural origins are mainly in North Carolina, South Carolina and Florida. There are many places belong to alluvial topography, and the summer weather is hot, the winter temperature is cold, the temperature difference between day and night is large, which belongs to the typical continental climate, these are suitable for the growth of flytrap.

The United States has designated its place of origin as a protected area, and even in the Appendix II to the Convention on International Trade in Endangered species of Wild Fauna and Flora, there is a complete ban on export of "roots and bulbs of flytrap". However, since many species have been released before that, under the active cultivation of operators around the world, and even mass production using tissue culture technology, it is generally easy to buy flytrap on the market.

Predation mode

Secretory nectary

The habits of insectivorous plants are roughly divided into the following four steps: to induce insects to catch insects to use digestive juices to decompose and absorb absorbed nutrients to maintain growth. However, not all carnivorous plants go through such a complete process. For example, some plants of the same type do not secrete digestive juices, but absorb nutrients after decomposition by various microorganisms. In this part, the flycatcher belongs to a relatively advanced carnivorous plant with a quite complete process.

The leaf margin of the flytrap contains nectaries that secrete nectar to attract insects. When the insect enters the leaf surface, it touches the sensory hairs belonging to the sensory organs twice, and the two leaves close quickly. The bristles growing on the leaf margin are multicellular protrusions and do not have the function of bending. When the leaves close quickly and hold the insects, the bristles bite tightly together in order to prevent the insects from escaping.

Transmit signal

The signal of catching insects is not provided directly by sensory hairs. There is an inflated part at the base of the sensory hair, which contains a group of sensory cells. Sensory hairs act like levers. Insects push sensory hairs, causing them to oppress sensory cells, which emit a weak electric current to notify all the cells on the trap. Because the current will scatter to the whole trap, it is not necessary to touch the same sensory hair to cause the closure, as long as any two hairs in the same clip emit electric current, it can cause the closure movement. Of course, the current emitted by the felt hair only affects the trap in which it is located, and does not interfere with the operation of other traps on the same plant.

Before being stimulated, the trap opens at an angle of 60 degrees, and when stimulated by an insect, the trap closes on its leaf vein. The closure of the trap is related to the contraction of the cells on the clip. When the cells on the trap receive the current emitted by the sensory cells, the cell vacuoles on the inside lose water and contract rapidly, causing the trap to bend inward and close.

Closure of insect traps

The closure of the trap is a precise control process. This process begins when the insect touches the sensory hair on the clip. The condition that causes closure is that in a trap, either one sensory hair is touched twice, or two sensory hairs are touched respectively. The interval between touching sensory hairs has a decisive effect on closure: if the interval between two touches is within 20 to 30 seconds, it can be closed after that time, it takes a third successful stimulus to close.

The trap needs two stimuli to make sure the insect is in the right place. When the trap is stimulated for the first time, the insect only walks into the trap slightly; if the trap is closed and only holds part of the insect, then the insect has a good chance of escape. When the trap is stimulated for the second time, the insect almost goes inside the trap, and the closed trap can actually catch the insect and lock it in.

The process of closure is divided into two stages.

The first stage: the clip closes quickly in order to catch the insect, and the trap is just holding the insect.

The second stage: the trap shrinks inward so that the inside of the clip can be as close to the insect as possible. At this time, the trap is completely closed without leaving any gap.

Digestion and absorption

The clip is closed for a few days to more than a dozen days, when the insect is digested by digestive juice secreted by the glands distributed on the trap. After the insect is digested, the trap will be turned on again, waiting for the next prey. The rest of the insect shells that cannot be digested are taken away by the wind and rain. The second stage requires the struggle of insects, because this means that what the trap catches is indeed insects and live prey.

Flytraps sometimes catch dead branches and fallen leaves by mistake. Without this confirmation mechanism, nutrients are bound to be wasted on digesting debris that cannot be digested. If the trap catches debris by mistake, as long as there is no continuous stimulation, the trap will be reopened after a few hours, waiting for the next prey.

When the captured insect is trapped by two leaves and cannot break free, the leaves will clamp tighter and tighter until they are almost closed in the process of struggle, and the dense inner glands on the inside of the two leaves will secrete digestive juice. using the proteases contained in these digestive juices, the insect proteins are broken down into nitrogen, oxygen, carbon, hydrogen, and possibly other elements of amino acids and absorbed. Generally, it can decompose and absorb the more digestible parts in about four days, and then continue to absorb the remaining nitrogen, phosphorus and other necessary trace elements. After these nutrients are absorbed, the petals will open again, which will take about 5 to 10 days, leaving only the empty shell debris of chitin.

However, the flytrap cannot tell the size of the catch, and sometimes it may catch something about the size of a leaf, such as a small frog or a long-footed wasp. At this time, it is often too late to decompose and absorb, and the acquired body will rot first, so the leaves will appear like food poisoning and wither. In addition, each leaf can capture about 12-18 times and digest 3-4 times. Beyond this number, the leaves will lose their ability to catch insects, make their due contribution to the final photosynthesis, and then gradually wither.

Catching speed

When insects gather honey, the leaves do not move when they first come into contact with sensory hairs, but if they are stimulated twice in a row, the leaves will close in an average of about 0.5 seconds (but some artificial horticultural varieties can't do that). If the time difference between the second touch and the first touch is more than 20 seconds, the leaf will become semi-closed or unresponsive. If you stimulate it for the third time at this time, the leaves will close quickly.

After experimental investigation, the sensory hair of the flytrap is like a sensing device. After two consecutive touches, the base of the leaf will generate about 100mV (mV) of active potential (Action potential) to the leaf surface, resulting in the rapid loss of water on the inside of the leaf, resulting in uneven internal and external pressure, so the leaf is closed. Such a trapping mechanism is a set of quite sophisticated structural arrangements, and stimulating sensory hairs is like setting a timing device, which will not be closed until the second confirmation, mainly to improve the accuracy of catching worms. otherwise, when raindrops and animals pass by, they will reduce and affect their efficiency of catching insects.

Plant researchers have confirmed that flytraps emit active potentials, so that nerve tissue similar to animals produces transmission information. But because it has to be touched twice in a row, that means there should be an organization that can remember. Plant researchers still don't know how such memories work in flytraps, which is an unsolved mystery.

Insectivorous plants set up a mystery and then kill. The tiny fluff of the flytrap was touched twice and suddenly closed with a bang.

Reproduction method

Sexual reproduction

Flytrap propagates through seeds and belongs to seed plants. The flytrap can be self-pollinated, but it usually takes artificial pollination to bear fruit. However, the artificial pollination of the flytrap is unlikely to be successful because it is not the right time to pollinate.

When the flytrap blossoms, not both the female and stamen mature at the same time. When the flower just blossoms, its stamen has matured, but the pistil is not mature, it is useless to pollinate it at this time. The pistil of the flytrap usually matures one day later than the stamen, so the right thing to do is to wait for the flower to bloom the next day.

And then pollinate. We can also observe the shape of the pistil to determine whether it is mature. The stigma at the end of the immature pistil is round, and the stigma at the end of the mature pistil will split like fluffy; only the mature pistil can be pollinated successfully.

If pollination is successful, the flower will wither within 1-2 days, the ovary (the base of the pistil) will expand, and the fruit will ripen in a few weeks. The seeds of the flytrap are black and droplet-shaped; a fruit usually contains a dozen seeds. The number of seeds is related to the health and size of the plant itself. Robust plants usually produce a little more seeds. Sometimes the method of pollination is correct, but the seeds still do not bear fruit. The biggest problem is that the flytrap is not strong enough, or it is not continuously given enough light during flowering. Even if it is pollinated successfully, it is difficult to produce seeds.

The seeds of flytrap are less resistant to preservation, so j try to sow as soon as possible after harvest. Sometimes, if you want to do cross-pollination, but the plants you want to cross do not blossom at the same time, you can first collect the pollen and store it in the refrigerator to prolong the life of the pollen.

Since flowering is a nutrient-consuming activity for plants, do not let the flytrap blossom if it is not necessary, especially if you want to plant a large flytrap, the stem of the flower should be cut off as soon as possible to prevent the flytrap from wasting nutrients on flowering. As the flytrap will bloom in the season, some weak plants will barely blossom, but in order to protect the plant, or cut off the flower stem.

Leaf insertion method

The common breeding method of flytrap is leaf insertion, that is, a petiole is inserted into the soil to grow new plants. In late spring to early summer, when the flytrap is growing vigorously, after the flytrap is dug out of the soil, we can see its white petaloid petiole buried in the soil. Attach the traps of the flytrap to the petioles (like leaves), peel off the base of the white petioles, and then place the petioles on the cultivation medium to maintain high humidity and bright light, and new buds will emerge after a few weeks.

The process of the formation of new buds is very slow, so be patient and wait. As long as the base of the petiole does not blacken or rot, we have to wait forever. Since there are no roots in the petiole at this stage, it is important to maintain the humidity, so that the moist cultivation medium can be attached to the petiole in order to provide water; the light intensity at this time is also very important, requiring bright and sufficient light, but can not let the sun shine directly, otherwise the petiole will be too hot and dry. The age of the petiole is also related to the success rate of reproduction. Usually, the petiole in the prime of life is enlarged and has the greatest chance of producing seedlings; the old leaves are less likely to produce new buds than the young leaves. Therefore, when breeding, we can use the outer petiole of the flytrap, and the rest of the center can be planted back; if the petiole can have roots, then the chance of success will be higher.

In order to reduce the damage to the petiole, the use of a clean cultivation medium will not let the petiole rot, so it is recommended to use water moss as the cultivation medium for leaf insertion, and wait until the seedlings grow out before considering transplanting to other places.

Split-plant method

Flytraps often grow lateral buds, which can be separated from their parent plants and cultivated separately as long as they are large enough and have complete roots (but some cultivated species rarely have ramets throughout the year).

Flower bud method

The flower bud of the flytrap sometimes turns into a plant! It is known that this phenomenon is caused by the temperature difference. If there is a great temperature difference between day and night, the flower buds of the flytrap will be induced to transform into a new plant. At this time, the small plant can be cut off and planted in the soil, and it will be a new flytrap.

Cultivation techniques

Lighting: swamp plants, the native environment is not shaded by tall plants, like the sun. During family cultivation, full sunshine can be provided in spring, autumn and winter, and 50% shade should be added or placed on the indoor sunny windowsill in summer in the south. Or use plant supplementary light (red-blue ratio 2:1) to carry out artificial light cultivation above 15-30cm from the plant, irradiation time is 4 hours per day.

Moisture: try to use pure water, Rain Water and other soft water (tap water can be used in southern China). The basin immersion method (called "waist water" method in Hong Kong and Taiwan) is used to create a small environment similar to the original place. The specific method is to place the flytrap basin in a tray or glass tank, inject water to 1-2cm depth, and replenish water regularly. (note: waist water is easy to rot in summer.)

Humidity: more than 50%, the original environment of the flytrap is a swamp grassland, and the humidity is relatively high. If you can use a large water plate to make waist water, the humidity nearby will be a little higher. You can also add a layer of water moss on the topsoil of the basin. It is also helpful to maintain the humidity of the air.

Matrix: the matrix is maintained at ph3.5-5 acidity. Peat and perlite without fertilizer at 2:1 or pure water moss, the matrix should be changed every spring as far as possible.

Temperature: the growth temperature is 15 ℃ ~ 35 ℃, and the suitable temperature is 21 ~ 35 ℃. If you want to make it dormant in winter, it must be controlled at about 5 ℃ (0 ~ 8 ℃). However, according to years of maintenance experience, not going through dormancy has no obvious effect on the normal growth in the coming year.

Feeding: please don't force them to eat too much, they will hunt for themselves. You can only feed arthropods (insects, spiders, etc.) on up to 2 leaves. Their digestive juices are difficult to digest the fat in meat that people eat every day, such as beef and chicken.

Fertilization: the root system of insectivorous plants is extremely intolerant to salt, and directly applying fertilizer into the substrate will lead to the death of the plant, so low concentration liquid fertilizer should be sprayed on the leaves. If the foliage plant fertilizer sold in the market is used, it can be applied according to the recommended concentration of 1x5 (1VR 5000) and sprayed every two weeks in the growing season.

Cultivation medium

The main results are as follows: 1. Flytrap prefers the cultivation medium with good water retention and acid. It can be cultivated directly with peat soil or water moss, that is, only a single cultivation medium can be used. However, the price of water moss is higher, and its service life is shorter, but it is cleaner than other cultivation media, so water moss is more suitable to be used as a cultivation medium for leaf cuttings or seedlings. The large flytrap is more suitable for the use of peat soil with lower cost. The texture of some peat soil is more detailed, so the complete use of peat soil may cause poor drainage and easy to accumulate water. We can add a small amount of perlite or granular soil to peat soil, or we can combine peat soil and sand in an one-to-one way. In fact, flytrap in its place of origin grows on sandy land, and the use of a combination of sand and peat soil may be the best choice. Because flytrap prefers acidic cultivation medium, quartz sand, silica sand or river sand are the main choice of sand; calcareous sand, such as coral sand or shell sand, should not be used.

2. The fresher the seed is, the higher the budding rate is. The seed is placed in a sealed transparent vessel with water moss inside. The seed is sown on the surface of the water moss (remember not to be too dense). The humidity is covered with cling film on which the water moss is not dripping (meaning the maximum saturation of the water moss). Poke a few small eyes with toothpicks on the cling film and put them in a place where the light is strong but cannot be directly exposed to the sun, and the seeds of better quality will sprout in about a week. When the height or diameter of the plant is about 2 cm, it is transplanted into an ordinary flowerpot and needs to be domesticated.

Sowing step

Ready to sow the flowerpot: fill the flowerpot with the substrate and place it in a glass jar or basin with purified water to absorb water to the surface, and then spray the surface with a spray bottle (spray).

Sowing: carefully unpack the seeds, spread the seeds evenly on the surface of the substrate, and cover with 0 or 3 cm of culture soil.

Spray: wet the surface with a spray bottle (spray) and spray carefully so as not to wash away the seeds.

Cultivation: put the seeded flowerpot together with the glass tank or water basin on the inside of the sunny windowsill. If it is a water basin, a plastic cover with a top opening should be added to moisturize. Pay attention to timely replenishment of water, generally about 10 days germination (20 degrees).

Seedling formation: it can be transplanted when the seedlings grow 2 or 3 true leaves.

Seedling stage management

Substrate preparation: use clean water moss as substrate, soak for at least 24 hours before transplantation (preferably with boiling water to remove germs and weed seeds), squeeze the water out of the water moss during transplantation (or shake dry with a dryer) and wait for planting.

Preparation of tissue culture seedlings: wash the culture medium on the tissue culture seedlings with clean water (pay attention to moisturizing the plants during cleaning and transplanting, so as not to wilt the leaves), and the tissue culture seedlings are not soaked with chemicals.

Transplantation: cover the base of the plant with water moss (not too high, it is suitable to cover the root), and have a certain degree of compactness (pinched with fingers, it can be sunken and then bounced up). After transplantation, pour through the root water with clean water.

Species classification

In its native place, there is only one native species (Dionaea muscipula) and several forms (Dionaea muscipula f, viridis) of flytrap.

Etc.), their shapes are relatively simple. However, in the process of propagation of flytrap by tissue culture or sowing, a very small number of flytraps will mutate, causing some of their forms to be different from those before the mutation, when these variation characteristics appear steadily in the next generation; it can be called a new variety, and a large number of mutated varieties are one of the biggest pursuits of players who like flytrap.

There are more than 600 horticultural varieties of flytrap, most of which are mutated by tissue culture; in addition, there are many hybrid varieties, and plants germinated by seeds are also likely to mutate.