Anchored water hyacinth | |
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E. azurea flowering | |
Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Monocots |
Clade: | Commelinids |
Order: | Commelinales |
Family: | Pontederiaceae |
Genus: | Pontederia |
Species: | P. azurea |
Binomial name | |
Pontederia azurea Sw. | |
Pontederia azurea is a water hyacinth from the Americas, sometimes known as anchored water hyacinth. It is the type species of Pontederia subg. Eichhornia, which was previously recognized as part of the polyphyletic genus Eichhornia. [1] It is of some interest as an aquarium plant.
The anchored water hyacinth is a free-floating aquatic perennial plant. [2] It is known by various common names such as, water orchid, and floating water hyacinth. The water hyacinth could be identified by its distinct thick, waxy green leaves that has a rounded or elliptical shape. It is able to grow under water and above water due to its long stem that is able to produce up to 5 flowers on a single stem. [2] The hyacinth produces large blossoms with lavender blue petals and a yellow blotch at the center, the flower bearing great resembles with that of a lilac. The petals of the flower are normally 2 inches wide with six petals making up the flower. It can grow up to three feet above water surface and is rooted in the soil underwater. [3]
The Anchored Water Hyacinth (Eichhornia azurea) is native to Central and South America, inhabiting warm bodies of water. In 1884, the species was introduced to New Orleans from South America. [3] [4]
The species has expanded to Alabama, Arkansas, California, Florida, Georgia, Hawaii, Indiana, Kentucky, Missouri, Mississippi, North Carolina, South Carolina, Texas, Virginia, and Vermont. [4] E. azurea also has been introduced into Japan, China, Singapore, and New Zealand. The E. azurea species is considered to be a noxious species by the United States and is prohibited in the following states: Alabama, Arizona, California, Florida, Massachusetts, North Carolina, Oregon, South Carolina, Texas, and Vermont. [5]
In 1884, the anchored water hyacinth was introduced from South America to the United States as an ornamental. The species is able to grow rapidly once introduced and rapidly forms expansive mats of the water hyacinths. Hyacinths are known to double its population size in just two weeks and can reproduce through their seeds and horizontal stems. When they wither, their stems bend and they are able to release their seeds into the soil below. Fragmenting a piece of the plant allows for the plant to be transported and planted elsewhere.[ citation needed ]
E. azurea poses a threat as a noxious weed. [5] Due to its enlarged bulb-like petioles, the plant is able to not only grow under the surface of the water, but also is able to float and extend above water. In competition with other species for similar requirements in water surface area or bank rooting positions, E. azurea is extremely successful. [6] As an invasive species, the E. azurea is able to accumulate on the surface of water that smothers native species while also lowering light penetration and dissolved oxygen levels. [4] This contributes to the decline of biodiversity as aquatic animals suffocate and die with the lack of dissolved oxygen and resources. Water quality also suffers as result of the lack of dissolved oxygen in the water. This also impacts the fauna that rely on the diverse native species that die against the E. azurea. It also poses a threat towards native aquatic animals as E. azurea is able to reduce their food and habitats. [6] Additionally, the E. azurea is a good habitat for disease vectors such as mosquitoes and parasitic flatworms which bring about diseases such as malaria and schistosomiasis. [4] [7]
The anchored water hyacinths also contributes to water loss in introduced areas through transpiration and also negatively affects recreational activities as it clogs waterways. The clogging of water ways prevents swimming, boating and fishing. [6]
Eichhornia azurea is similar to Eichhornia crassipes ; the most obvious difference is that E. crassipes is a free floating plant. Both are considered invasive weeds, but E. crassipes is the more widely known and studied as an invasive species; control methods for E. crassipes are generally suitable for E. azurea as well. [8] Three types of controls are variously appropriate: biological, physical, and chemical. Biological and physical control require consistent management to have any consistent effect, and chemical control also demands competent management to yield significant benefit while avoiding environmental harm. [9]
Chemical control consists of herbicides and the one applied to water hyacinths are 2,4-D, Diquat and Glysophate which requires skilled operators. [8] [10] They have the disadvantage that leaving the dead plants on the water increases degree of anoxia and eutrophication.
Physical control is suited for large infestations only when large-scale mechanical aids are available for physically removing the weeds, but it is necessary in early stages of control of intense infestations that are already smothering large water surfaces, rendering the water anoxic. There are many ways of harvesting the weeds and composting them to die, but they all demand that the plant material be removed from the water to avoid eutrophication.
The last type of control, biological, is favored whenever practical. This control consists of the use of natural enemies, insects in particular. [9]
Eichhornia, commonly called water hyacinths, was a polyphyletic genus of the aquatic flowering plants family Pontederiaceae. Since it was consistently recovered in three independent lineages, it has been sunk into Pontederia, together with Monochoria. Each of the three lineages is currently recognized as subgenera in Pontederia:
Water garden or aquatic garden, is a term sometimes used for gardens, or parts of gardens, where any type of water feature is a principal or dominant element. The primary focus is on plants, but they will sometimes also house waterfowl, or ornamental fish, in which case it may be called a fish pond. They vary enormously in size and style.
Pontederiaceae is a family of flowering plants.
Pontederia is a genus of tristylous aquatic plants, members of which are commonly known as pickerel weeds. Pontederia is endemic to the Americas, distributed from Canada to Argentina, where it is found in shallow water or on mud. The genus was named by Linnaeus in honour of the Italian botanist Giulio Pontedera.
Alternanthera philoxeroides, commonly referred to as alligator weed, is a native species to the temperate regions of South America, which includes Argentina, Brazil, Paraguay and Uruguay. Argentina alone hosts around 27 species that fall within the range of the genus Alternanthera. Its geographic range once covered only the Parana River region of South America, but it has since expanded, having been introduced to over 30 countries, such as the United States, Japan, China, Australia, New Zealand and many more. This invasive species is believed to have been accidentally introduced to these non-native regions through sediments trapped by, or attached to, tanks and cargo of ships travelling from South America to these various areas.
Heterostyly is a unique form of polymorphism and herkogamy in flowers. In a heterostylous species, two or three morphological types of flowers, termed "morphs", exist in the population. On each individual plant, all flowers share the same morph. The flower morphs differ in the lengths of the pistil and stamens, and these traits are not continuous. The morph phenotype is genetically linked to genes responsible for a unique system of self-incompatibility, termed heteromorphic self-incompatibility, that is, the pollen from a flower on one morph cannot fertilize another flower of the same morph.
The mottled water hyacinth weevil, Neochetina eichhorniae, is a beetle that has been introduced as a biological pest control herbivore agent to waterways and lakes in countries worldwide to control the spread of the invasive noxious weed species Eichhornia crassipes, the water hyacinth, an aquatic plant native to the Amazon basin.
Pontederia crassipes, commonly known as common water hyacinth is an aquatic plant native to South America, naturalized throughout the world, and often invasive outside its native range. It is the sole species of the subgenus Oshunae within the genus Pontederia. Anecdotally, it is known as the "terror of Bengal" due to its invasive growth tendencies.
Eccritotarsus catarinensis is a species of plant bug from Santa Catarina, Brazil. It is a sap-feeding mirid that removes a considerable amount of chlorophyll from water hyacinth.
Rawa Pening is a lake in the Ambarawa Basin in Central Java, Indonesia. It serves as a source of power, irrigation, and flood control, and is used for fishing. Due partly to high numbers of aquatic plants, it may dry out by 2021.
Samea multiplicalis, the salvinia stem-borer moth, is an aquatic moth commonly found in freshwater habitats from the southern United States to Argentina, as well as in Australia where it was introduced in 1981. Salvinia stem-borer moths lay their eggs on water plants like Azolla caroliniana, Pistia stratiotes, and Salvinia rotundifolia. Larval feeding on host plants causes plant death, which makes S. multiplicalis a good candidate for biological control of weedy water plants like Salvinia molesta, an invasive water fern in Australia. However, high rates of parasitism in the moth compromise its ability to effectively control water weeds. S. multiplicalis larvae are a pale yellow to green color, and adults develop tan coloration with darker patterning. The lifespan, from egg to the end of adulthood is typically three to four weeks. The species was first described by Achille Guenée in 1854.
Water hyacinth has become a major invasive plant species in Lake Victoria and while it is native to the continent of South America, human activity has introduced the greenery to Lake Victoria, where it is claimed to have negatively affected local ecosystems.
Limnobium laevigatum is a floating aquatic plant, and is a member of the family Hydrocharitaceae. Common names include West Indian spongeplant, South American spongeplant and Amazon or smooth frogbit. This plant was introduced to North American waterways through use in aquariums and aquascapes.
An aquatic weed harvester, also known as a water mower, mowing boat and weed cutting boat, is an aquatic machine specifically designed for inland watercourse management to cut and harvest underwater weeds, reeds and other aquatic plant life. The action of removing aquatic plant life in such a manner has been referred to as "aquatic harvesting".
Monochoria was originally a genus of aquatic plants in the water hyacinth family, Pontederiaceae. Currently, it has been reduced to a subgenus of Pontederia, Pontederia subg. Monochoria, represented by ten species. Its species are native to tropical and subtropical Africa, Asia, and Oceania. They live in the water or in wet soils. They produce leaves on long petioles and some are cultivated for their attractive flowers.
Gundlachia ticaga is a species of minute freshwater snail or limpet, an aquatic gastropod mollusc in the family Planorbidae, the ram's horn snails and their allies.
Cornops aquaticum is a semiaquatic species of grasshopper native to the Neotropics, from southern Mexico south to central Argentina and Uruguay. It feeds and breeds exclusively on members of the aquatic plant family Pontederiaceae, especially water hyacinth, and is being investigated as a possible biological pest control agent for the water hyacinth in countries where that plant is invasive.
Aquatic plant management involves the science and methodologies used to control invasive and non-invasive aquatic plant species in waterways. Methods used include spraying herbicide, biological controls, mechanical removal as well as habitat modification. Preventing the introduction of invasive species is ideal.
Megamelus scutellaris, the water hyacinth planthopper, is a true bug native to South America. It is used as a biological control agent to manage and reduce the spread of the water hyacinth, an invasive aquatic plant native to South America that has invaded many freshwater systems globally.
Media related to Eichhornia azurea at Wikimedia Commons