Editor's note: Plants sprout sometimes, flower sometimes, fruiting sometimes, from a plant to a population, to a community and an ecosystem, from plant evolution to vegetation succession, from a sample point to an area, plants are the recorders of life changes in the process of evolution, but also the guardian of the vitality in the change of time, plants are the epitome of nature, and everything in the world is inextricably linked, communicating between man and nature. Voice of the Chinese Academy of Sciences and the Institute of Botany of the Chinese Academy of Sciences jointly opened the "Notes on Grass and Wood Release", where we interpret plants, interpret nature, interpret the secrets of life, and together with grass and trees, live up to every season.
In books, movies, anime or games, there have been many piranhas. They are often given a hideous and frightening image, which is daunting, and makes people wonder about the scene of themselves walking in the forest and suddenly being eaten by plants. feel relieved! Plants are cute and lovely, and they are not so capable, but plants that can prey on small animals are real, that is, carnivorous plants.
Carnivorous plants, as the name suggests, refer to a type of plant that can catch and eat insects. There are more than 600 species of carnivorous plants in the world, belonging to 13 families and 21 genera, mostly distributed in swamps or rocky desertification areas where the soil is acidic. These areas have harsh environments and poor soils, and it is often difficult to supply enough nitrogen for plant growth, and the plants growing here have to think of other ways to survive successfully. We know that animal bodies are rich in protein, and when broken down, they can provide a lot of nitrogen. Perhaps tasting this sweetness, some plants in order to adapt to the harsh living environment, ease their competitive pressure with other "neighbors", so that the population continues, they unlock a new skill, evolved a strange shape of the leaves, in order to hunt insects to obtain nitrogen, this method and nitrogen-fixing plants use nitrogen-fixing bacteria to make nitrogen fertilizer.
How do carnivorous plants hunt insects?
In nature, it is very common for animals to eat plants, and plants that cannot move at will use what tricks to capture animals? In simple terms, the way insectivorous plants prey on animals can be divided into two categories: passive predation and active predation, of which passive predation is the most important method of predation.
Passive predation includes the design of "traps", the manufacture of "sticky fly plates" and the use of "shrimp cages".
Traps: Plants that prey prey are designed to include Nepenthes and Bottleworts. In the case of the famous Nepenthes family, the traps designed by Nepenthes are mostly red, yellow and often dotted with stripes and spots, which can secrete digestive juices, and the bright colors are fatally alluring to insects. The surface of the waxy insect pitcher is very smooth, once the insect is attracted, it is easy to fall into the bottom of the bottle, and then digested and absorbed by the digestive juice in the bottle. Many people think that the lid of Nepenthes will be closed after the insect falls into the bottle, in fact, it is not the case, the lid of Nepenthes does not actively close, the lid is closed when the pitcher is not yet mature, as the growth of the pitcher The lid slowly opens, the main role of the lid is to cover the rain like an umbrella, to prevent the digestive juice in the pitcher from being diluted. Therefore, when you see a cage on a pitcher plant that is at different stages of growth, don't open and close the lid of the brain.
Nepenthes (Image from the Internet)
Bottle grass (image from the internet)
Sticky fly board: Grassy vegetables are generally relatively petite, with bright red or purple leaves, the leaves are densely covered with fine glandular hairs, and the glandular hairs are distributed with nectar-like crystal clear mucus at the top, in fact, these mucus are the "sweet traps" woven by thatched vegetables for insects, and each leaf is its carefully designed "sticky fly board". Once attracted, insects will be stuck and unable to move, and mucus will block the insect's breathing channel, causing it to suffocate. After catching insects, some species of grassy vegetables will also slowly bend the glandular hairs and wrap the insects tightly to increase the contact area of the mucus, which can more efficiently absorb nutrients from the insect's body.
Also using the "sticky fly board" to catch prey are the Civetaceae family of insect catchers, most of which live in the mountains with higher sea margins. Like most alpine plants, the plant is low and rosette-like, with very gorgeous flowers, but the leaves of the insect trap are dangerous, and the mucus on the leaves after approaching them is like glue, and then digests and absorbs them, which is the standard "snake scorpion beauty".
Thatched vegetables (image from the Internet)
Insect trap (image from the Internet)
Shrimp cage: Many friends have seen shrimp cages, cylindrical net cages, there are multiple inward tightening holes on both sides, fish and shrimp through the small holes into the shrimp cage is difficult to escape. The spirulina's insect trap also resembles a miniature labyrinth that can only be entered and exited, and the prey is a protozoa. The spirulina's insect trap looks like a small white threaded root, in fact, it is still a leaf evolution, there are many reverse hairs inside, the protozoa enter the trap after the thread and fine hairs will prevent it from swimming in reverse, can only swim deeper, and eventually become a feast for the spirulina. Spirulina is the only known carnivorous plant that hunts protozoa.
Spirulina (Image from the web)
Insect-catching leaf microstructure (image from the web)
Shrimp cage (image from the web)
The carnivorous plants mentioned above are all passive predators of the rabbit type, and some carnivorous plants have taken a different path and choose to actively hunt by using mouse traps and vacuum cleaners.
Mousetrap: Flycatcher is called by Darwin as one of the most wonderful plants in the world because of its use of mousetrap hunting, its English name is "Venus Flytrap", which literally translates to "Venus's fly shoot", it seems that the goddess is also plagued by flies. The red leaves of the flytrap open like a mousetrap, and the edges of the leaves are sharp serrated teeth, like two rows of teeth, which did not disappoint the insects, and the blood basin also brewed sweet honeydew inside the mouth. Its appearance is easily reminiscent of the large-mouthed flower in Plants vs. Zombies, which will be swallowed by it as soon as it approaches. The way the flytrap preys on insects is very similar to the way the largemouth flower devours zombies, the insect will touch the small induction hairs on the inside when it approaches the trap of the flytrap, but only one touch of the flytrap is not easy to start, if the insect touches the induction hair for the second time within 20 seconds, the flycatcher will quickly close the leaves, and the serrations on both sides of the leaf are staggered to form a cage to trap the insect in it, and after a few hours the flycatcher begins to secrete digestive juices, and in the following weeks, Flytraps can enjoy a nutritious protein meal.
Flycatcher (image from the web)
Mousetrap (image from the web)
Vacuum Cleaners: Tanuki plants living in water are known as the most agile killers in the plant kingdom, and there are many floating traps on tanuki branches. Tanuki's insect trap is based on a suction force as powerful as a vacuum cleaner to catch insects, it can maintain an internal vacuum through drainage, when the zooplankton close to the trap to touch the induction hair, the unidirectional membrane flap of the cyst will open inward, instantly forming a huge pressure difference so that the zooplankton is sucked into the sac. The bristle cells at the mouth of the sac can also regulate the pressure of the water in the sac and maintain the concentration of digestive juice.
Flowers of Tanuki algae (Image from the Internet)
Tanuki insect trap (image from the internet)
Do carnivorous plants that eat meat also eat vegetarians?
Different species of carnivorous plants have different body shapes, different growth environments, and great differences in appetite. Small carnivorous plants such as thatched vegetables and insect traps can only prey on small insects such as flies and ants, while large carnivorous plants such as Nepenthes Melim and Nepenthes Malay can prey on lizards, frogs and even mice and birds. Bottlegrass grows in the swamps to prey on insects during the dry season, fish and shrimp can be caught during the rainy season as the water level rises, small aquatic carnivorous plants such as tanuki can only prey on small zooplankton, and spirulina feeds on protozoa.
Flying in the sky, running on the ground, and swimming in the water are all included in the menu of carnivorous plants, so will the carnivorous plants be vegetarian? The answer is yes. For example, N. apple, which lives in the shade of the canopy, mainly relies on the fallen leaves in the sac to obtain nutrients, and in order to collect more fallen leaves, its lid even degenerates and folds outwards, directly opening the trap to wait. For another example, scientists have found that many tanuki plants not only have zooplankton in the insect trap, but also some algae, and it seems that carnivorous plants are also very concerned about nutritional balance.
Nepenthes apple (image from the internet)
Speaking of recipes, it is necessary to mention a strange flower in the carnivorous plant kingdom, " Nepenthes Laurie , which attracts tree shrews by secreting honey, but the tree shrews are not prey and do not slip through the smooth sacs, they only stay at the sacs and suck up honey. But Nepenthes Laurie can not do a loss-making business, enough to eat and drink enough of the tree shrew excreted feces just fell in the insect trap, the study found that the mature Nepenthes leaves have a large amount of nitrogen from the tree shrew feces, the original feces is its real "food" Ah, really a heavy taste of mutual benefit and reciprocity relationship.
Tree shrew sucking N. Laurie's honey (image from the Internet)
Will insects starve to death without feeding insectivorous plants?
The recipes of carnivorous plants can be described as meat and vegetarian collocation, balanced nutrition, so do artificially grown carnivorous plants need to often feed them insects, fish and shrimp? If they don't eat meat, they always worry that they will starve to death. Attention, the point is drawn! After all, carnivorous plants are plants, and although they can rely on digesting prey for nutrition, they have not lost the ability to photosynthesis. Therefore, in the artificial cultivation environment, if the matrix nutrients are sufficient, they can survive by absorbing soil nutrients and photosynthesis, and do not need to be fed alone, and excessive feeding is easy to cause indigestion of carnivorous plants, resulting in the decay of animal carcasses to produce odors and affect ornamentation. Of course, in the barren environment of the wild or in the case of unsatisfactory artificial cultivation conditions, carnivorous plants can also wither, fall leaves and even die due to malnutrition.
Nowadays, due to habitat loss, environmental pollution, species invasion, illegal digging and other reasons, the survival status of carnivorous plants is very grim. The International Union for Conservation of Nature (IUCN) has assessed the endangered status of 102 plants in 7 genera of more than 600 known carnivorous plants, of which 7 are critically endangered, 11 are endangered and 39 are vulnerable, so the high endangered rate is worrying. The survival status of carnivorous plants is not only related to their own survival, but also affects many species closely related to them. In native land, carnivorous plants are important habitats for many small animals. At the same time, carnivorous plants also catch many insects that transmit human diseases for humans, such as eggs, larvae and adult worms such as horse flies and mosquitoes. Small carnivorous plants are protecting human health with their own weak efforts, and now, let's take care of their future together!
Source: Institute of Botany, Chinese Academy of Sciences