Among all the strange plants in the world, there are even some that consume flesh. Well, maybe not exactly flesh, but insects, but they are considered carnivorous nonetheless. All carnivorous plants are found in areas where the soil is poor in nutrients. These amazing plants are considered carnivorous because they capture insects and arthropods, secrete digestive juices, dissolve the prey, and in the process, obtain some or most of the nutrients.
Why do plants become predators?
Almost all plants feed on the soil's vital nutrients. To obtain these nutrients, they have a root system, often quite extensive. It is through this system that nutrients from the soil enter the stem, are absorbed, and transformed into fiber, leaves, wood, and the beautiful inflorescences that delight the eye. The more fertile the soil, the more opportunities a plant has. This principle applies to all members of the plant family. But, unfortunately, not all soils are fertile. Carnivorous plants that feed on insects are forced to obtain the nutrients they need for their survival for one simple reason: they have nowhere else to get them, as predators live in very poor soils. Nevertheless, they thrive. Moreover, many gardeners grow carnivorous plants indoors.
How do carnivorous plants feed?
Over the course of evolution, the leaves of carnivorous plants have undergone significant changes: they have become specialized trapping organs: sticky traps, instantly triggered pitfalls, and water lilies filled with digestive fluid. For example, the leaf of the sundew is covered in droplets of a sticky substance. Because of this glittering scattering, the Americans call the plant "gemstone grass.".
1. Nepenthes
Most Nepenthes species grow in tropical Asia. They are particularly fond of the island of Borneo. Nepenthes are found from the Seychelles and Madagascar to New Guinea, northern Australia, and New Caledonia. The plant's trap contains a watery or sticky liquid in which insects that decide to land on the plant drown. Some large Nepenthes species are capable of catching not only insects but also small mammals, such as rats.
By the way, people keep some carnivorous plants at home as houseplants.
2. Venus flytrap
In the wild, the Venus flytrap is found primarily in the humid, temperate climate of the Atlantic coast of the United States. It hunts insects using traps that can snap shut very quickly, in about 0.1 seconds. Dense cilia line the edges of the leaves, preventing prey from escaping. The leaflets then close tightly, forming a stomach where digestion occurs. The Venus flytrap is able to distinguish live prey from mere debris caught in the trap. Thus, the trap snaps shut only when an insect lands on it.
3. Darlingtonia californica
The plant grows in northern California and Oregon. These insectivorous plants are astonishing in the variety of techniques they use to mislead their prey. For example, the Californian darlingtonia, which hunts near rivers, lakes, and cool springs, is bulbous. At the center of this natural wonder is a hole with two fang-like, rather sharp leaves. The darlingtonia itself lives underwater. What makes it unique is that it doesn't use its leaves to catch prey; insects enter through its "crab claw," an asymmetrical petal. But the main trick lies in the color disorientation of the prey, achieved by the many light-shadow transitions into which the insect immerses once inside. These insectivorous plants simply drive their prey crazy with the speckles on their light-conducting membrane, so that they can no longer tell up from down. Furthermore, the hairs guide them in the right direction. As a result, the victim of the Californian darlingtonia descends deeper, where the digestion process takes place.
4. Aldrovanda vesiculosa
Aldrovanda vesiculosa grows in Western Europe; Eastern, Central, and Southeast Asia; the Far East; the Caucasus; and Africa. The plant inhabits water. Its diet consists primarily of small aquatic vertebrates.
Aldrovanda vesiculosa is a magnificent rootless, carnivorous aquatic plant. It typically feeds on small aquatic vertebrates using a trap-like structure.
The plant consists primarily of free-floating stems that reach 6-11 cm in length. Trap leaves, 2-3 mm in size, grow in 5-9 whorls along the center of the stem. The trap leaves are attached to petioles, which contain air, allowing the plant to float. This fast-growing plant can reach 4-9 mm per day, and in some cases, produce a new whorl every day. While the plant grows at one end, the other end gradually dies.
The plant's trap consists of two lobes that snap shut like a trap. The trap's openings face outward and are covered with fine hairs, allowing the trap to close around any prey that gets close enough. The trap snaps shut in tens of milliseconds, making it one of the fastest movements in the animal kingdom.
5. Sundew
This plant can be found on every continent except Antarctica. Sundews can form basal or vertical rosettes ranging from 1 cm to 1 m in height and can live up to 50 years. The sundew's glandular tentacles secrete a sticky, sweet secretion. When an insect lands on the sticky tentacles, the plant begins to move its remaining tentacles toward the prey, trapping it. Once the insect is trapped, small sessile glands absorb it, and the nutrients are used for plant growth.
6. Biblis
Byblis, or rainbow plant, is a small species of carnivorous plant native to Australia. The rainbow plant gets its name from the attractive slime that coats its leaves in the sun. Although these plants resemble sundews, they are not related to the latter and are distinguished by their zygomorphic flowers with five curved stamens.
Its leaves are round in cross-section, often elongated and conical at the tip. The leaf surface is completely covered with glandular hairs that secrete a sticky, mucous substance that traps small insects that land on the plant's leaves or tentacles.
7. Sarracenia
Sarracenia or North American pitcher plant is a genus of carnivorous plants that are found in areas of the east coast of North America, Texas, the Great Lakes, southeastern Canada, but most are found only in the southeastern states.
This plant uses its lily-shaped, trap-like leaves as a trap. The plant's leaves have evolved into a funnel-like structure, a hood-like structure that grows over the opening, preventing rainwater from entering and diluting the digestive juices. Insects are attracted by the color, scent, and nectar-like secretions at the edge of the lily. The slippery surface and the narcotic substance lining the nectar lure the insects inside, where they die and are digested by proteases and other enzymes.
8. Butterwort
Butterworts belong to a group of carnivorous plants that use sticky, glandular leaves to attract and digest insects. The nutrients they obtain from the insects supplement mineral-poor soil. There are approximately 80 species of these plants in North and South America, Europe, and Asia.
The leaves of butterworts are succulent and typically bright green or pink. There are two specialized types of cells located on the upper surface of the leaves. One, known as a pedunculate gland, consists of secretory cells located at the apex of a single stem cell. These cells produce a mucilaginous secretion that forms visible droplets on the leaf surface, acting like Velcro. The other cells, called sessile glands, are located on the leaf surface and produce enzymes such as amylase, protease, and esterase, which aid in digestion. While many butterwort species are carnivorous year-round, many types form a dense, non-carnivorous rosette during winter. When summer arrives, the rosette blooms and produces new carnivorous leaves.
9. Pemphigus
A unique bubble trap is characteristic of a plant with the resonant name Utricularia. It's small, with the largest bubbles reaching a centimeter or slightly more. Consequently, its prey is modest, typically feeding on tadpoles and water fleas. However, its diversity and range are impressive. There are over two hundred species, and this predator can be found almost anywhere, except perhaps in the tundra or Antarctica. The technique used in hunting is also unusual. A small vacuum is generated inside the bubbles, and the plant, like a miniature vacuum cleaner, sucks up passing insects along with the water. This happens very quickly; the entire process from opening the trap to sealing it takes mere microseconds.
10. Genlisea
Genlisea consists of 21 species, typically growing in moist terrestrial and semi-aquatic environments and is distributed in Africa and Central and South America.
Genlisea are small, yellow-flowered plants that use a crab-claw-like trap. These traps are easy to get into but impossible to escape from due to small hairs that grow toward the entrance or, as in this case, spiral forward.
These plants have two distinct types of leaves: photosynthetic leaves above ground and specialized underground leaves that attract, trap, and digest small organisms such as protozoa. The underground leaves also perform the functions of roots, such as water absorption and anchorage, since the plant itself lacks roots. These underground leaves form hollow, spiral-shaped tubes beneath the ground. Small microbes are drawn into these tubes by the flow of water but are unable to escape. By the time they reach the exit, they have already been digested.
How to grow carnivorous plants at home?
Even experienced gardeners admit that growing these plants is not easy. However, any difficulties involved in growing and caring for them are more than offset by the opportunity to observe these unique plants and feed them annoying gnats and mosquitoes. Carnivorous houseplants require special attention and proper care. Carnivorous plants act as "orderlies," destroying insects in the apartment. Of the more than 600 species of carnivorous plants, only two dozen are cultivated as houseplants. The following are most commonly grown: sundew (round-leaved, English, royal); nepenthes (some species); purple sarracenia; butterwort; heliamphora; Venus flytrap; aldrovanda (aquatic plant). They require specific conditions in the apartment.
Lighting
All carnivorous plants require good lighting, preferably diffused light. Some species even tolerate direct sunlight. In low light, plants with orange, red, crimson, or burgundy leaves turn green, losing their brightness and decorative appeal. The same applies to modified leaves designed for hunting: pitcher plants, funnel plants, and trap plants. Tropical carnivores, such as darlingtonia and nepenthes, are particularly sensitive to low light. During winter, they require supplemental lighting.
Temperature
The room where such an unusual plant grows should be maintained at a temperature appropriate for the species. In other words, it should be as close to natural as possible. Carnivorous houseplants from temperate climates—such as butterworts, sundews, sarracenias, and Venus flytraps—thrive at temperatures of 18–22°C. However, they do not suffer if the temperature drops to 10°C. Interestingly, butterworts, sundews, and frost-hardy sarracenia varieties can be successfully grown outdoors or near artificial ponds. A tropical plant, Nepenthes, requires a higher temperature of 22–25°C. Substrate: Carnivorous indoor plants are planted in soil similar to their natural soil composition. It should be acidic, with a pH of 5.0 to 6.2, and free of large amounts of minerals and organic components. For example, you can use a mixture of peat moss and sphagnum sand in a 3:1 ratio. Sometimes, coconut fiber replaces peat, and perlite replaces sand.
Humidity and watering
Carnivorous houseplants are watered with warm (19-22°C), soft water. Water three times a week in summer and once a week in winter. A common challenge for beginning gardeners when growing carnivorous houseplants is maintaining the right humidity. For normal growth and vigorous development, most species require high humidity – over 60°C/150°F. Tropical species (Nepenthes, Darlingtonia) require around 85°C/260°F. Otherwise, the plants will lose their decorative appeal: the leaf tips, where the traps and pitchers are located, dry out, and new leaves fail to emerge. Regular misting is not enough to maintain the required humidity. Many use a tray filled with expanded clay or pebbles. Fill it with water, ensuring that it does not touch the bottom of the flower pot. Carnivorous plants are best grown in terrariums or winter gardens. If this is not possible, use special humidifiers.
Feeding
Indoor plantings of green predators, just like in the wild, require additional nutrition. Feed them, as expected, with protein-rich foods. Horseflies, flies, cockroaches, spiders, and small slugs are suitable for this purpose. Active predators (such as the Venus flytrap) are fed using tweezers: carefully bring the insect to the open trap and release it. As soon as the sensitive hairs sense the prey's touch, the trap snaps shut.