The carnivorous plants are categorized as carnivorous because they trap insects and arthropods, produce digestive juices, dissolve the prey and derive some, or most, of their nutrients from this process. Here is a list with some of the most curious of them:
Dionaea Muscipula, more commonly known as a Venus flytrap, is probably the most well-known carnivorous plant and it feeds mainly on insects and arachnids. Is a small plant that has 4-7 leaves that grow from a short subterranean stem. The plant is so advanced that it can tell the difference between live stimulus and non-living stimulus. The lobes snap shut in about 0.1 seconds. They are fringed by stiff thorn-like protrusions or cilia, which mesh together and prevent large prey from escaping. Once prey is unable to escape and the inner surfaces of the lobes are continuously being stimulated, the edges of the lobes grow or fuse together, sealing the trap and creating an enclosed “stomach” in which digestion and absorption can take place.
Sarracenia, or the North American Pitcher plant, is a Genus of carnivorous plants indigenous to the eastern seaboard, Texas, the great lakes and south eastern Canada, with most species being found only in the southeast states. It is also the first plant with a pitfall trap that we will look at. The plant’s leaves have evolved into a funnel, with a hood like structure growing over the opening to prevent rain water from diluting the digestive juices. Insects are attracted by colour, smell and a nectar-like secretion on the lip of the pitcher. Slippery footings, aided in at least one species, by a narcotic drug lacing the nectar, causes insects to fall inside where they die and are digested by proteases and other enzymes.
Utricularia, or collectively known as bladderworts, is a genus of carnivorous plants consisting of about 220 species. They occur in fresh water and wet soil as terrestrial or aquatic species, on every continent accept Antarctica. They are the only carnivorous plants that make use of bladder traps. The traps have small trigger hairs attached to a trapdoor. The bladder, when set, is under negative pressure in relationship to its surrounding area. When the trigger hairs are tripped, the trap door opens up, sucks in the insect and surrounding water, and closes the door again, all in a matter of 10 thousands of a second.
Genlisea, better known as the corkscrew plant, is made up of 21 species and generally grows in wet terrestrial to semi aquatic environments, and are spread across Africa, central and South America. Genlisea are small herbs with yellow flowers that make use of lobster pot traps. These plants have two distinct types of leaves – photosynthetic leaves above ground, and specialized underground leaves to attract, trap and digest minute organisms, like protozoans. These underground leaves form hollow tubes under the ground, these tubes have a forward propelling corkscrew shape, and with the aid of constant water flow, small microbes can make their way into these tubes, but cannot find a way out again. When they reach the correct part of the tubes, they will be digested and absorbed.
Byblis, or rainbow plant, is a small genus of carnivorous plant native to Australia. The name rainbow plant comes from the attractive appearance of their mucilage covered leaves in the sun. The leaves have a round cross section, and they tend to be very elongated and tapered at the end. The surface of the leaves are completely covered in glandular hairs that release a sticky mucilaginous substance, which in turn traps small insects on the leaves or tentacles as a passive flypaper trap.
Nepenthes, tropical pitcher plants or monkey cups, are another genus of carnivorous plants with pitfall traps. There are about 130 species that are wide spread, and can be found in China, Malaysia, Indonesia, Philippines, Madagascar, Seychelles, Australia, India, Borneo and Sumatra. The nickname “monkey cups” comes from the fact that monkeys have often been observed drinking rain water from them.
Most species of Nepenthes are tall creepers (10-15m), with a shallow root system. From the stem you will often see sword like leaves growing, with a tendril (often used for climbing) protruding from the tip of the leaf. At the end of the tendril, the pitcher forms first as a small bulb, which then expands and forms the cup. The trap contains fluid, produced by the plant, which may be watery ors syrupy and is used to drown and digest the insects. The lower part of the cup contains glands that absorb and distribute nutrients.
Drosera, commonly known as sundews, comprises one of the largest genera of carnivorous plants, with at least 194 species. These can be found widely spread on every continent accept for Antarctica. Sundews, can form either prostrate or upright rosettes, ranging from 1cm to 1m in height, and can live up to 50 years. Sundews are characterized by movable glandular tentacles, topped with sweet sticky secretions. When an insect lands on the sticky tentacles, the plant is able to move more tentacles in the direction of the insect to trap it further. Once trapped, small sessile glands will digest the insect and absorb the resulting nutrients, which can then be used to aid growth.
Aldrovanda vesiculosa, also known as the waterwheel plant, is a fascinating rootless, carnivorous, aquatic plant. It generally feeds on small aquatic vertebrates, using a trap mechanism called a snap trap. The traps basically consists of two lobes which fold together to make the snap traps. The openings of the trap point outwards, and are covered in a fine coating of trigger hairs, which will cause the trap to snap shut around any prey that comes too close. The trap closes in only 10 milliseconds, making it one of the fastest examples of plant movement in the animal kingdom.