Utricularia - Carnivorous plant

Utricularia - Carnivorous plant


The Utricularia are carnivorous plants that capture their prey through mechanisms of

ASCIDES OR SIMILAR deriving from the modification of some leaves.

The flap of the modified leaves loses, in whole or in part, its shape to become a trap that takes on the function of capturing small animal prey.

The preys are attracted in various ways (with colors, with nectar, etc.) and remain trapped in the ascidian. At that point, devices are activated to dissolve them and absorb the elements that derive from them.

The genre Utricularia (family Lentiburaliaceae) is cosmopolitan and includes more than two hundred species of very different appearance. Some are reminiscent of moss, others of normal plants. It is an aquatic plant and its submerged leaflets have a large number of small vesicles filled with water and provided with a square opening at the front closed by a sort of swing valve.

Around this opening there are two large branched hairs and other smaller ones that work like a pot.If a small prey touches one of these hairs, the valve of the Ascidian opens inwards, sucking in this way the prey and the valve closes

The common bladderwort (Utricularia vulgaris L.) is a carnivorous plant. It is a perennial aquatic plant, not anchored to the bottom and devoid of true roots. Its stems are branched and flexible, up to 2 meters long.
Between the leaves are inserted numerous translucent vesicles called ascidia, which are used to capture small aquatic organisms. They are equipped with a series of bristles and absorbent hairs.
It is found in the temperate-cold areas of Europe, Asia and North Africa, in fairly deep stagnant waters up to 1000 m s.l.m. It is used in phytotherapy for its diuretic and anti-inflammatory properties.

Common blister grass - Utricularia vulgaris L. (


  • 1 Description
    • 1.1 Flowers
  • 2 Distribution and habitat
  • 3 Traps
    • 3.1 Physical description
    • 3.2 Mechanism of action
    • 3.3 Lloyd's experiments
  • 4 Species
  • 5 Phylogeny
  • 6 Notes
  • 7 Bibliography
  • 8 Related items
  • 9 Other projects
  • 10 External links

The main part of a 'Utricularia it always lies below the surface of its substrate. Terrestrial species sometimes produce few photosynthetic leaves that grow flat on the soil surface, but in all species only the flower stem rises and is prominent. This means that terrestrial species are generally only visible when they are in bloom.

Most species form long, thin stolons below the surface of their substrate or the water of the ponds in which aquatic species live. Both the utricles and the leaves are connected to the stolons.

The generic name Utricularia comes from the Latin utriculus, what does it mean small wineskin or leather bottle.

Flowers Edit

The flowers are the only part of the plant visible above the ground or water. They are usually produced at the apex of a long, thin stem and consist of two asymmetrical lip-like petals, with the lower usually significantly larger than the upper. They are very similar in structure to the flowers of the pinguicoles.

The flowers of aquatic species such as U. vulgaris they are often described as small yellow snapdragons the flower of Utricularia dichotoma instead it recalls violets. Epiphytes have the largest flowers, often compared to those of orchids

Certain plants in particular seasons can produce self-pollinating flowers, but the same plant can also produce flowers with entomophilic pollination.

The Utricularia they can survive almost anywhere where fresh water is present for at least part of the year: they are not only present in Antarctica and the oceanic islands. The greatest specific diversity occurs in South America, followed immediately after by Australia [1]. In common with most carnivorous plants, they grow in moist soils that are poor in dissolved minerals, where their carnivorous nature gives them a competitive advantage. Terrestrial utricularies often live in the same environments as sarracenias and sundews. Many of the terrestrial species are tropical.

Aquatic species float on the surface of ponds and other basins with still waters and muddy bottoms, although few species have adapted to live in fast-moving streams or near waterfalls [3]. Plants usually live in acidic waters, but they also tolerate alkaline waters well [4].

Some tropical South American species are epiphytes and grow on the spongy barks of rainforest trees or within the water-filled rosettes of other epiphytes, such as the different species of the bromeliad Tillandsia [5]. The epiphytes that live inside the rosettes produce jets that go in search of other bromeliads in the vicinity to colonize them [6].

Plants are highly adapted to survive adverse seasons. Temperate perennials may need a winter dormancy period, tropical species require no dormancy period but vegetate all year round. Aquatic species that live in cold areas such as Great Britain and Siberia can produce so-called winter buds hibernacula at the ends of their stems: when the photoperiod is reduced in autumn and growth slows or the plant is killed by the ice that forms on the surface of the ponds, hibernacula they separate from it and reach the bottom of the pond, where they will remain until spring. At this point they come back to the surface and start growing again. Other species are annuals and spend the colder seasons in the form of seeds.

Physical Description Edit

Scientists agree that vacuum traps of Utricularia they are the most sophisticated trapping mechanisms of carnivorous plants and among the most complex structures of all plants [7]. Traps are usually shaped like a stone and are attached to submerged stolons.

The walls of the utricles are thin and transparent, but they are strong enough not to deform when the vacuum is created. The entrance, or "mouth" of the trap is a circular or oval flap, the upper half of which is joined to the body of the trap by flexible cells that form a rather effective hinge. The "door" rests on a platform formed by the thickening of the wall of the utricle placed immediately below. A thin but solid membrane, called velum it stretches to form a ring around the central part of the platform and helps seal the door.

The outermost cells of the trap secrete a mucilage, which is produced in greater quantities under the door and which contains sugars. Mucilage helps keep the door sealed, while sugars help attract prey.

Terrestrial species generally possess tiny traps with a large, beak-like structure that extends above the entrance. This structure prevents the trapping and ingestion of inorganic particles. Aquatic species tend to have larger traps, with the mouth surrounded not by a "beak", but by branched "antennae" which have the task of guiding the prey towards the entrance of the trap and to remove the larger particles, which could trigger it unnecessarily. Epiphytic species have unbranched antennae, which probably have the same role as those of aquatic species. [8].

Mechanism of action Modification

The mechanism of action of the Utricularia is purely mechanical: no "active" intervention by the plant is required in the presence of the prey, unlike the mechanism of the Dionaea muscipula you hate Aldrovanda vesiculosa. The only active mechanism is the continuous outward pumping of water through the walls of the utricle for active transport.

When the water is pumped out of the trap, the walls of the utricle are sucked in by the vacuum created, and the dissolved substances inside it become more concentrated. At a certain point, due to osmotic pressure, water can no longer escape from the trap and its walls accumulate potential energy as in a spring.

From the bottom of the trap, protuberances in the shape of long bristles extend which can be confused with the sensitive hair present in the traps of Dionaea, but with whom they have nothing in common. These bristles, in fact, are simple levers. The suction force exerted by the "loaded" trap on the door is counteracted by the adhesion of its flexible lower part with the velum. The slightest contact of a prey with one of the "lever" hairs deforms the flexible lip of the door just enough to create a small opening and break the seal.

Once this is broken, the walls of the trap instantly "snap" and take on a more circular shape. The door opens completely and the water is sucked into the utricle along with the prey. When the trap fills with water the door closes again. The whole process takes about one hundredth of a second.

Once inside, the prey is digested by the enzymatic secretions produced by the plant. Digestion lasts a few hours, although it has been observed that some protozoa manage to live inside the trap for several days. [9].

The trap continues to pump water out and is ready for the next catch in about 15 minutes.

Lloyd's Experiments Edit

In 1940 F.E Lloyd conducted experiments on carnivorous plants, including Utricularia. He proved that the mechanism of the trap of this plant is purely mechanical both by inhibiting the hair by means of iodine and demonstrating that the mechanism continued to work, and by proving that the trap could be ready to snap a second time immediately after a capture by letting out the 'water present in it artificially in other words, the interval of about 15 minutes between two successive clicks of the trap is the time necessary for its emptying and the hairs do not need time to recover their irritability, as in the case of Dionaea or Aldrovanda [8] .

Lloyd also demonstrated the role of the velum, proving that the presence of small cuts on it prevents the trap from "loading", finally demonstrated that the water leakage can be prevented by bringing the osmotic pressure of the trap beyond normal limits by adding glycerin. [10].

Utricularia it is the largest genus of carnivorous plants. It is one of the three genera that form the Lentibulariaceae family, along with Pinguicula is Genlisea.

Before Peter Taylor reduced the number of species to 214, 250 were ascribed to the genus [11].

The following cladogram shows the relationships between the various subgenres and sections. It is called "super tree" because it summarizes the results of two studies, put together by Müller et al. in 2006 [12]. Since the sections "Aranella" and "Vesiculina" are polyphyletic, they are followed in the cladogram by the symbol (*). Some monotypic sections were not included in this study, so their position in this system is uncertain.

Carnivorous plants bewitching

W ith various tricks, they attract, trap and eat their prey, usually insects. Here is the amazing world of the "green killer whales"!

Of tropical origin, it hates drought and grows well in a greenhouse: if you don't have one, even the bathroom at home is fine as long as it is bright. Its cone-shaped traps (30 cm) are protected by a hat that prevents water from entering and diluting the digestive liquid, and are gradually formed at the ends of the leaves. The top is covered with a sugary substance that attracts insects, which glide along the smooth walls of the cone before drowning in the liquid. The leaves last longer than the predatory cones, which dry out very quickly. Nepenthes can only be grown indoors.

This plant owes its name to its traps in the shape of small wineskins (in reality they are underground leaves that have undergone a transformation) which suck up prey before closing up again. It is not easy to observe this system if they are not grown in a transparent container. The aerial leaves ensure photosynthesis, while the flowers have alluring colors and shapes that resemble those of some varieties of orchids. Utricularia can be terrestrial or aquatic.

At the end of its colored hair there are droplets of a sticky substance. The prey, attracted by the bright colors, settles there and remains prisoner: struggling to free itself, it worsens the situation by sticking more and more, and favoring the secretion of the digestive enzymes of the plant. In summer, small spikes of flowers appear in the center of the rose created by the arrangement of the leaves.

The trap is an erect cone-shaped leaf, of different colors, often spotted and large. The upper end is covered with a substance that attracts insects. Once inside, they have no chance to get out: the hairs that line the inside of the cone hinder them. The traps of this plant can survive several months before drying out and their flowering is truly spectacular.

Its name derives from the plump appearance of its leaves covered with glue, which roll up around the unfortunate insects. In the middle of the leaves, which form a light green rose, grow thin stems covered with flowers of various colors.

Bubble in an aquarium - is it good or bad?

Some people believe that predatory algae are not suitable for an aquarium. But after all, the owners of glass water locks with fish are sure that the bubbling cavity is an aquarium plant. Who is right, first or second? You can understand by weighing all the pros and cons of living such a predator in an aquarium. On the one hand, if you add such a carnivorous plant to the fish, then there will be a chance that small fish, crustaceans and fry can die in flower traps. This is the one minus aquarium pemphigus. If you know how to fix it, everything will be fine.

On the other hand, pemphigus house - a plant that can become a good decoration of your water world. It blooms in an aquarium with beautiful wreaths of green stems that simply float on the surface, as they have no roots. This plant does not require special attention to itself, it is easy to care for, it spreads easily. Let's summarize this dispute with another plus. When you take a pemphigus from a natural tank and place it in your aquarium, it will begin to change over time. His bubble traps will begin to shrink and gradually disappear altogether. These beautiful algae will no longer be able to catch even the weakest prey. From this it follows that pemphigus in the aquarium - it is possible, your aquarium will benefit from it.



Utricularia, carnivorous plant belonging to the Lentibulariaceae family.

It represents the largest genus of carnivorous plants, in fact there are about 215 species that live in fresh waters or in soils saturated with water on all continents except Antarctica.

All utricularies are carnivorous and capture small organisms by means of their suction traps, called utricles. Terrestrial species tend to have tiny traps and feed on small protozoa and rotifers. Aquatic species possess larger traps and feed on daphnia, nematodes, mosquito larvae and tadpoles. Despite their small size, the traps are extremely sophisticated.

The utricularie are unusual and highly specialized plants, in which the vegetative organs are not clearly separated into roots, stem and leaves as in most other angiosperms. The utricles, on the other hand, are considered to be one of the most sophisticated structures in the kingdom of plants.

Type of trap

Suction. The traps are extremely sophisticated. When the prey touches the hairs connected to the entrance of the trap, it opens and sucks the prey and the surrounding water into it. Once the trap is full of water the door closes again.

Light and temperature

Utricularia likes a well-lit location, but rarely the sun
direct, especially in the hottest areas. The ideal is diffused light or direct sun only during the early morning or late evening hours.


Water abundantly with demineralized water but avoid submerging the plants.

Culture method

To cultivate them you can use a compost of peat mixed with sand or perlite. The most used pots are those of plastic or glass to make the cultivation more choreographic. In winter, most species must be sheltered from cold and frost and temperatures must be kept between 5 and 10 ° C, although some species such as U. subulata is U. longifolia they resist even slight frosts.

When they have covered the entire surface of the pot they must be divided and transplanted into a larger pot, otherwise they will perish.

Important: The information on this page relates to the cultivation of Terrestrial Utricularia.

Video: Sundew Carnivorous Plant wraps around 2 Locusts