Aldrovanda vesiculosa | |
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Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Order: | Caryophyllales |
Family: | Droseraceae |
Genus: | Aldrovanda |
Species: | A. vesiculosa |
Binomial name | |
Aldrovanda vesiculosa | |
Distribution | |
Synonyms [2] | |
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Aldrovanda vesiculosa, commonly known as the waterwheel plant, is the sole extant species in the flowering plant genus Aldrovanda of the family Droseraceae. The plant captures small aquatic invertebrates using traps similar to those of the Venus flytrap. The traps are arranged in whorls around a central, free-floating stem, giving rise to the common name. This is one of the few plant species capable of rapid movement.
While the genus Aldrovanda is now monotypic, up to 19 extinct species are known in the fossil record. [3] [4] [5] While the species displays a degree of morphological plasticity between populations, A. vesiculosa possesses a very low genetic diversity across its entire range. [5]
A. vesiculosa has declined over the last century to only 50 confirmed extant populations worldwide. These are spread across Europe, Africa, Asia, and Australia. [5] However, potentially invasive populations exist in the eastern United States. [6] It is kept by hobbyists.
Aldrovanda vesiculosa is a rootless aquatic plant. Seedlings develop a short protoroot; however, this fails to develop further and senesces. The plant consists of floating stems reaching a length of 6–40 cm (2–16 in). [5] [7] The 2–3 mm (1⁄16–1⁄8 in) trap leaves grow in whorls of between 5 and 9 in close succession along the plant's central stem. The actual traps are held by petioles which have air sacs that aid in flotation. One end of the stem continually grows while the other end dies off. Growth is quite rapid (4–9 mm (3⁄16–3⁄8 in) per day in Japanese populations [8] ), so that in optimal conditions a new whorl is produced once or more each day.[ citation needed ]
The actual traps consist of two lobes which fold together to form a snap-trap similar to that of the Venus flytrap, except that it is smaller and located underwater. These traps, which are twisted so that the trap openings point outward, are lined on the inside by a fine coating of trigger hairs, snapping shut in response to contact with aquatic invertebrates and trapping them. The closing of this trap takes 10–20 milliseconds, [9] [10] making it one of the fastest examples of plant movement in the kingdom. This trapping is only possible in warm conditions of at least 20 °C (68 °F). [11] Each trap is surrounded by between four and six 6–8 millimetres (1⁄4–3⁄8 in) long bristles that prevent triggering of traps by debris in the water.[ citation needed ]
A. vesiculosa is able to grow in nutrient-poor habitats not only due to its carnivory, but also due to its ability to re-utilize nutrients from senesced shoots, [12] and its high affinity for mineral nutrients in water. [13]
The small, solitary white flowers of A. vesiculosa are supported above the water by short peduncles which arise from whorl axes. The flower only opens for a few hours, after which the structure is brought back beneath the water for seed production. The seeds are cryptocotylar: the cotyledons remain hidden within the seed coat and serve as an energy store for the seedling. Flowering, however, is rare in temperate regions and poorly successful in terms of fruit and seed development. [5]
Aldrovanda vesiculosa reproduces most often through vegetative reproduction. In favourable conditions, adult plants will produce an offshoot every 3–4 cm (1+1⁄8–1+5⁄8 in), [14] resulting in new plants as the tips continue to grow and the old ends die off and separate. Due to the rapid growth rate of this species, countless new plants can be produced in a short period of time in this fashion.[ citation needed ]
Winter-hardy Aldrovanda form turions as a frost survival strategy. At the onset of winter, the growth tip starts producing highly reduced non-carnivorous leaves on a severely shortened stem. This results in a tight bud of protective leaves which, being heavier and having released flotational gases, breaks off the mother plant and sinks to the water bottom, where temperatures are stable and warmer. Here it can withstand temperatures as low as −15 °C (5 °F). [15] In the wild, Aldrovanda turions have been observed to have a relatively low rate of successful sinking. [15] Those nutritious turions that fail to sink are then grazed by waterfowl or are killed by the onset of frost. In spring when water temperatures rise above 12–15 °C (54–59 °F), turions reduce their density and float to the top of the water, where they germinate and resume growth. [15] Non-dormant turion-like organs can also form in response to summer drought. [15]
Aldrovanda vesiculosa is the second most widely distributed carnivorous plant species, only behind members of the genus Utricularia , native to Europe, Asia, Africa, and Australia. Aldrovanda is spread mainly through the movement of waterfowl: plants sticking to the feet of a bird are transported to the next aquatic destination on the bird's route. As a result, most Aldrovanda populations are located along avian migratory routes. Throughout the last century the species has become increasingly rare, listed as extinct in an increasingly large number of countries. [5] In the 1970s, carnivorous plant hobbyists introduced this species to small backyard ponds in the United States in the states of New Jersey, Virginia, and the Catskills of New York, and they may be a potentially invasive species due to their effects on aquatic invertebrates. [6]
The waterwheel plant faces significant conservation threats related to habitat degradation and human-induced modifications. Residential and commercial development, along with agricultural and aquacultural activities, pose immediate risks to the species. The impacts of these activities on the plant's aquatic habitats are of particular concern. [16]
Across Europe, the species is confronted by several environmental challenges, as identified by the Commission of the European Union. Acidification, canalization, drainage, eutrophication, pollution, and various forms of habitat modification are highlighted as threats. These changes in the natural environment have the potential to disrupt the waterwheel plant's habitats and populations. [16]
While the extent and effects of illegal trade remain uncertain, it is believed that some illegal activities involving Aldrovanda vesiculosa may occur. This potential threat adds complexity to the conservation challenges faced by the species. [16]
A. vesiculosa prefers clean, shallow, warm, standing water with bright light, low nutrient levels, and a slightly acidic pH (around 6). It can be found floating amongst Juncus, reeds, and even rice.[ citation needed ]
The Waterwheel (Aldrovanda vesiculosa) thrives in a range of aquatic habitats, including small fens, peat-bog pools, billabongs, lakes, lagoons, and river deltas. It prefers oligo-mesotrophic and dystrophic systems with low nutrient levels. These plants are commonly found in shallow backwaters or the littoral zones of larger lakes, where they face less competition from other aquatic species and where water levels remain relatively stable throughout the growing season. The Waterwheel is highly intolerant of habitat degradation, and even minor changes in water chemistry can lead to local extinction. [16]
Aldrovanda vesiculosa was first mentioned and illustrated in 1691 by Leonard Plukenet, based on collections made in India. He named the plant Lenticula palustris Indica. The modern botanical name originates from Gaetano Lorenzo Monti, who described Italian specimens in 1747 and named them Aldrovandia vesiculosa in honor of the Italian naturalist Ulisse Aldrovandi. [17] When Carl Linnaeus published his Species Plantarum in 1753, the "i" was dropped from the name (an apparent copying error) [18] to form the modern binomial. [14]
Drosera, which is commonly known as the sundews, is one of the largest genera of carnivorous plants, with at least 194 species. These members of the family Droseraceae lure, capture, and digest insects using stalked mucilaginous glands covering their leaf surfaces. The insects are used to supplement the poor mineral nutrition of the soil in which the plants grow. Various species, which vary greatly in size and form, are native to every continent except Antarctica.
Droseraceae is a family of carnivorous flowering plants, also known as the sundew family. It consists of approximately 180 species in three extant genera, the vast majority being in the sundew genus Drosera. The family also contains the well-known Venus flytrap and the more obscure waterwheel plant, both of which are the only living species of their respective genera. Representatives of the Droseraceae are found on all continents except Antarctica.
The Venus flytrap is a carnivorous plant native to the temperate and subtropical wetlands of North Carolina and South Carolina, on the East Coast of the United States. Although various modern hybrids have been created in cultivation, D. muscipula is the only species of the monotypic genus Dionaea. It is closely related to the waterwheel plant and the cosmopolitan sundews (Drosera), all of which belong to the family Droseraceae. Dionaea catches its prey—chiefly insects and arachnids—with a "jaw"-like clamping structure, which is formed by the terminal portion of each of the plant's leaves; when an insect makes contact with the open leaves, vibrations from the prey's movements ultimately trigger the "jaws" to shut via tiny hairs on their inner surfaces. Additionally, when an insect or spider touches one of these hairs, the trap prepares to close, only fully enclosing the prey if a second hair is contacted within (approximately) twenty seconds of the first contact. Triggers may occur as quickly as 1⁄10 of a second from initial contact.
Utricularia, commonly and collectively called the bladderworts, is a genus of carnivorous plants consisting of approximately 233 species. They occur in fresh water and wet soil as terrestrial or aquatic species across every continent except Antarctica. Utricularia are cultivated for their flowers, which are often compared with those of snapdragons and orchids, especially amongst carnivorous plant enthusiasts.
Genlisea is a genus of carnivorous plants also known as corkscrew plants. The 30 or so species grow in wet terrestrial to semi-aquatic environments distributed throughout Africa and Central and South America. The plants use highly modified underground leaves to attract, trap and digest minute microfauna, particularly protozoans. Although suggested a century earlier by Charles Darwin, carnivory in the genus was not proven until 1998.
Drosophyllum is a genus of carnivorous plants containing the single species Drosophyllum lusitanicum, commonly known as Portuguese sundew or dewy pine. In appearance, it is similar to the related genus Drosera, and to the much more distantly related Byblis.
Sarracenia is a genus comprising 8 to 11 species of North American pitcher plants, commonly called trumpet pitchers. The genus belongs to the family Sarraceniaceae, which also contain the closely allied genera Darlingtonia and Heliamphora.
Rapid plant movement encompasses movement in plant structures occurring over a very short period, usually under one second. For example, the Venus flytrap closes its trap in about 100 milliseconds. The traps of Utricularia are much faster, closing in about 0.5 milliseconds. The dogwood bunchberry's flower opens its petals and fires pollen in less than 0.5 milliseconds. The record is currently held by the white mulberry tree, with flower movement taking 25 microseconds, as pollen is catapulted from the stamens at velocities in excess of half the speed of sound—near the theoretical physical limits for movements in plants.
A turion is a type of bud that is capable of growing into a complete plant. A turion may be an underground bud. Many members of the genus Epilobium are known to produce turions at or below ground level.
Catopsis berteroniana, commonly known as the powdery strap airplant or the lantern of the forest, is an epiphytic bromeliad thought to be a possible carnivorous plant, similar to Brocchinia reducta, although the evidence is equivocal. Its native range is from southern Florida to southern Brazil. It generally grows on the unshaded twigs of trees, and has been shown experimentally to trap more insects in its tank than other bromeliads of comparable size. There are several other species in the genus, none of which is believed to be carnivorous.
Drosera regia, commonly known as the king sundew, is a carnivorous plant in the sundew genus Drosera that is endemic to a single valley in South Africa. The genus name Drosera comes from the Greek word droseros, meaning "dew-covered". The specific epithet regia is derived from the Latin for "royal", a reference to the "striking appearance" of the species. Individual leaves can reach 70 cm (28 in) in length. It has many unusual relict characteristics not found in most other Drosera species, including woody rhizomes, operculate pollen, and the lack of circinate vernation in scape growth. All of these factors, combined with molecular data from phylogenetic analysis, contribute to the evidence that D. regia possesses some of the most ancient characteristics within the genus. Some of these are shared with the related Venus flytrap (Dionaea muscipula), which suggests a close evolutionary relationship.
Sarracenia purpurea, the purple pitcher plant, northern pitcher plant, turtle socks, or side-saddle flower, is a carnivorous plant in the family Sarraceniaceae.
Nepenthes rafflesiana, or Raffles' pitcher-plant, is a species of tropical pitcher plant. It has a very wide distribution covering Borneo, Sumatra, Peninsular Malaysia, and Singapore. Nepenthes rafflesiana is extremely variable, with numerous forms and varieties described. In Borneo alone, there are at least three distinct varieties. The giant form of this species produces enormous pitchers rivalling those of N. rajah in size.
Aldrovanda is a genus of carnivorous plants encompassing one extant species and numerous extinct taxa. The genus is named in honor of the Italian naturalist Ulisse Aldrovandi, the founder of the Botanical Garden of Bologna, Orto Botanico dell'Università di Bologna. Aldrovanda vesiculosa has been reported from scattered locations in Europe, Asia, Africa, and Australia.
Drosera anglica, commonly known as the English sundew or great sundew, is a carnivorous flowering plant species belonging to the sundew family Droseraceae. It is a temperate species with a circumboreal range, although it does occur as far south as Japan, southern Europe, and the island of Kauai in Hawaii, where it grows as a tropical sundew. It is thought to originate from an amphidiploid hybrid of D. rotundifolia and D. linearis, meaning that a sterile hybrid between these two species doubled its chromosomes to produce fertile progeny which stabilized into the current D. anglica.
A protocarnivorous plant, according to some definitions, traps and kills insects or other animals but lacks the ability to either directly digest or absorb nutrients from its prey like a carnivorous plant. The morphological adaptations such as sticky trichomes or pitfall traps of protocarnivorous plants parallel the trap structures of confirmed carnivorous plants.
Philcoxia is a genus of seven rare plant species in the Plantaginaceae that are endemic to Brazil and resemble terrestrial species of the genus Utricularia. The genus, formally described in 2000, consists of the species P. bahiensis, P. goiasensis, P. minensis, P. tuberosa, P. rhizomatosa, P. maranhensis and P. courensis, each of the first three named for the Brazilian state to which it is endemic. The species are characterized by subterranean stems, peltate leaves at or below the soil surface, and five-lobed calyces. Their habitat has been reported as areas of white sand in the midst of cerrado vegetation at an elevation between 800 and 1450 m. Initial descriptions of the genus included suspicions that the plethora of stalked capitate glands on the upper surfaces of leaves was an indication that these species may be carnivorous. A study published in 2007 tested P. minensis for protease activity, a typical test for the carnivorous syndrome, and could detect none. Later studies detected other digestive enzymes such as phosphatases and qualitatively assessed prey digestion and nutrient uptake, suggesting that it is a true carnivorous plant. The genus epithet honors David Philcox (1926-2003), a botanist at Kew Gardens who worked extensively in tropical Scrophulariaceae.
Utricularia inflata, commonly known as the swollen bladderwort, inflated bladderwort, or large floating bladderwort, is a large suspended aquatic carnivorous plant that belongs to the genus Utricularia. It is a perennial that is native to the southeastern coastal plains of the United States. It has often been confused with U. radiata, which is similar but smaller than U. inflata. Since 1980, U. inflata has been reported to exist in locations beyond its traditional range, such as the Adirondack Mountains in New York, southeastern Massachusetts, and in Washington State. Studies on the populations in the Adirondacks suggest that an introduction of U inflata. to a location where it naturalizes can lead to altered sediment chemistry by reducing the net primary productivity of native species. It is also listed by the state of Washington as a problematic species because of the dense mat-forming habit of this aquatic Utricularia. It is one of the few carnivorous plants that can be invasive.
Carnivorous plants are plants that derive some or most of their nutrients from trapping and consuming animals or protozoans, typically insects and other arthropods, and occasionally small mammals and birds. They still generate all of their energy from photosynthesis. They have adapted to grow in waterlogged sunny places where the soil is thin or poor in nutrients, especially nitrogen, such as acidic bogs. They can be found on all continents except Antarctica, as well as many Pacific islands. In 1875, Charles Darwin published Insectivorous Plants, the first treatise to recognize the significance of carnivory in plants, describing years of painstaking research.
Drosera glanduligera, commonly known as the pimpernel sundew or scarlet sundew, is a species of carnivorous plant endemic to southern Australia. It is an ephemeral annual plant that grows in the winter and flowers from August to November.