In July 1799, the famous German scientist Alexander von Humboldt came to the Americas, where he spent five years of exploration and research, witnessed all kinds of novel things, and wrote a book about what he saw and heard, "Travels to the Americas".
Alexander von Humboldt
This book had a huge impact on Darwin in his youth, and the record of carnivorous plants in it even gave birth to Darwin's book "Carnivorous Plants".
In the course of his adventure, Humboldt heard that deep in the tropical forests of South America, a man-eating tree grew in the place where the Mackti lived. It is said that this tree has large leaves and can emit a strange fragrance. As soon as a person smells this fragrance, he loses consciousness, and once he falls under the tree, the large leaves of the man-eating tree will wrap the person until it is digested into a pile of white bones.
So Humboldt visited the local Mark tee in search of the legendary man-eating tree, but after several trips, he did not find any tree that could eat people. But he found some insect-eating plants and a tree that secreted highly toxic sap. Humboldt speculated that it was probably the local indigenous people who mixed cordyceps and poisonous trees to concoct the story of man-eating trees.
Flycatchers
There are currently about 600 species of plants that are considered to be carnivorous plants, and their leaves generally have a special structure, which can emit fragrance or secrete honey to attract insects, and then catch insects, and then secrete digestive juices to digest and absorb prey.
Let's introduce a famous insectivorous plant- flycatcher grass, and understand why they prey on insects. How do they hunt? And how do you tell if you're catching insects and not stones?
Flytraps catch "prey"
< h1 class="pgc-h-arrow-right" > about flytraps</h1>
Flytraps are a perennial herbaceous insectivore native to North America that is loved for its unique insect-catching skills and cool appearance. Although the environment of its origin has been damaged, the flycatcher has been successfully naturalized in other regions and has become a large population, and some plant lovers in China will also plant flycatchers on the balcony.
The most distinctive part of the flytrap is its leaves, which have obvious burrs on the leaf edges, and the leaves are the weapons of the flytrap to prey on insects. At the end of the petiole of the flycatcher, there is usually a flytrap clip, and the front of the trap is distributed with many red or orange sessile glands that can secrete digestive juices that break down and absorb insects.
Leaves of the flytrap
The flowers of the flytrap are also very distinctive, and it takes 4 to 5 years from seed germination to maturity with the ability to flower and bear fruit. It generally begins to flower shortly after the new leaves grow in the spring, and the length of the flower stem can reach 15 to 25 cm.
There are about 10 flower buds at the top of the flower stem, but only one white flower blooms every other day, and the flower can bloom for a few days before pollination, but once the pollination is successful, the next day the flower will be gone, and then the ovary will slowly expand and finally grow into a mature fruit.
Flowers of flytraps
Although flycatchers can be propagated by seeds, they are more troublesome to pollinate, seeds are not easy to preserve, and people plant flycatchers to appreciate its insect-catching leaves, so people in order to avoid flycatchers flowering and consuming a lot of nutrients, often lose the stems of flycatchers.
In contrast, flycatchers can also reproduce by simpler leaf cuttings, which involve inserting a petiole into the soil to grow new plants. Flycatchers are perennial herbs with a maximum lifespan of 20 to 30 years, and cultivation of flycatchers requires a certain tolerance.
<h1 class="pgc-h-arrow-right" >why do flytraps prey on insects? </h1>
In our impression, plants generally absorb nutrients from the soil, how can there be "meat-eating" carnivorous plants? Why do flytraps prey on insects?
This is actually related to the environment of its origin, the flytrap grassland is produced in North Carolina and South Carolina in the United States, mainly growing on the wetland grassland here, and the soil in the area is mostly peat and silica sand.
The moisture here is mainly derived from rainwater, which falls to the ground after the fusion of the atmosphere and carbon dioxide, creating an acidic environment. Flytraps live in this poor and acidic environment, and it is difficult to absorb nutrients and trace elements from the ground, so they have evolved the ability to prey on insects to supplement nutrients.
In fact, most of the more than 600 species of carnivorous plants on Earth live in barren land, and in order to replenish nutrients, especially nitrogen, they have evolved a wonderful structure that is different from other plants.
For example, Nepenthes forms several large belly bottles with lids containing liquids that can digest insects. The bottle grass that grows in the Americas also has a bottle-like structure with a very thin neck and a fluff facing the bottom of the bottle, making it easy for insects to get in and out.
<h1 class="pgc-h-arrow-right" > How do flytraps prey on insects? </h1>
Almost all carnivorous plants have the same hunting mechanism, they can release the fragrance or sap that attracts insects, when insects are lured to the trap, carnivorous plants will trap or stick insects under the action of their own unique mechanisms, and then secrete digestive juices to break down and absorb insects.
The leaves of the flytrap can secrete a sugary honey juice that lures the insect over and completely lets its guard down. When these insects suck honey, the clips of the flycatcher suddenly exert force, clamp the insects to death, and begin to secrete digestive enzymes that can break down and digest insects.
Once the trap is caught in the insect, it will not be easily released, and can only wait until the trapped insect is completely digested and absorbed, and the flytrap will reopen the clip and wait for the arrival of another insect. If people want to forcibly separate clamps by hand, they can only tear them apart and cannot open them.
The opening and closing of the flycatcher clip is regulated by water, when the insect is felt into the trap, the flycatcher will transfer a large amount of water to the cells on the outside of the clip, which makes the cells on the outside of the clip expand and become hard, and its strength can prevent the insect from struggling to escape.
Flytraps are not only highly skilled and responsive, but they are also one of the more intelligent insectivorous plants, and it can clearly distinguish whether it is an insect or other non-animal thing that falls into the trap.
<h1 class="pgc-h-arrow-right" > how can flytraps distinguish between insects and stones? </h1>
Flycatchers prey on insects in order to absorb nutrients and replenish energy, but each time they catch prey, they need to consume energy, and they fall into the traps carefully designed by the flytraps, in addition to insects, there will be other non-animal things, such as small stones, seeds of other plants, etc.
If the flytrap closes the clip once every time it falls into something, it will definitely consume its own energy, and when it is turned on again, it will consume energy, which is very unfavorable to the flycatcher.
But the flytrap is so "clever" that it can tell whether it's an insect or a stone that falls into a trap, and how does it do it?
It turns out that there are many tiny tentacles on the inside of the clip of the flytrap, which can feel the outside world, and once an insect or other thing touches these tentacles, it will trigger the "hunting mechanism" of the flytrap.
The magic is that flytraps only trigger their insect catching mechanism and clamp clamps when two tentacles are touched in succession or the same tentacle is touched twice.
That is, if an insect falls into the trap, it will definitely crawl or struggle on the clip, which will trigger the predatory mechanism of the flytrap, while if it is a small stone or grain of sand, it will not move when it falls into the clip, and the flytrap will not close the clip.
In addition, if there is a misjudgment, such as a small stone that makes the clip of the flycatcher clamp, in fact, it has another mechanism to determine whether it is misdirected, that is, the flycatcher will only secrete digestive juice when it feels that there is a struggle in the clip. If no insects are caught, the flycatcher's clips reopen after a few hours.
< h1 class="pgc-h-arrow-right" > concluding remarks</h1>
Among the many carnivorous plants, the flycatcher has a more sophisticated means, which not only has the special structure of capturing, digesting and absorbing insects, but also has the ability to judge whether falling into the trap is the prey they need.
Although flytraps are not uncommon and have become one of the popular and beloved balcony plants, the environment of its wild origin has been destroyed, and the impact of human activities on biodiversity is enormous.
@Popular science has material