Vallisneria (named in honor of Antonio Vallisneri) is a genus of freshwater aquatic plant, commonly called eelgrass, tape grass or vallis. The genus is widely distributed in tropical and subtropical regions of Asia, Africa, Europe, and North America.
Vallisneria is a submerged plant that spreads by runners and sometimes forms tall underwater meadows. Leaves arise in clusters from their roots. The leaves have rounded tips, and definite raised veins. Single white female flowers grow to the water surface on very long stalks. Male flowers grow on short stalks, become detached, and float to the surface. The fruit is a banana-like capsule having many tiny seeds.
Sometimes it is confused with the superficially similar Sagittaria when grown submerged.
This plant should not be confused with Zostera species, marine seagrasses that are usually also given the common name "eelgrass". Vallisneria has arched stems which cross over small obstacles and develop small planters at their nodes.
or tape grass
|Vallisneria spiralis |
Various strains of Vallisneria are commonly kept in tropical and subtropical aquaria. These include dwarf forms such as Vallisneria tortifolia, a variety with leaves around 15 to 20 cm in length and characterised by having thin, tightly coiled leaves. A medium-sized variety, Vallisneria spiralis is also very popular, typically having leaves 30 to 60 cm in length. The largest varieties are often called Vallisneria gigantea regardless of their actual taxonomic designation; in fact most of the plants sold as Vallisneria gigantea are actually Vallisneria americana. Similarly, some Vallisneria gigantea are sold as Vallisneria spiralis and these giant varieties are only really suitable for very large tanks, having leaves that frequently exceed 1 m in length, but they are quite hardy and will do well in tanks with big fish that might uproot more delicate aquarium plants.
With few exceptions, the commonly traded Vallisneria are tolerant and adaptable. While they do best under bright illumination they will do well under moderate lighting as well, albeit with slower growth rates. They are not picky about the substrate, and will accept plain gravel provided an iron-rich fertiliser is added to the water periodically. Once settled in, they multiply readily through the production of daughter plants at the end of runners (as mentioned above). Once they have established their own roots, these daughter plants can be cut away and transplanted if necessary. Vallisneria will accept neutral to alkaline water conditions (they do not like very acidic conditions) and do not require carbon dioxide fertilization. They are also among the few commonly traded aquarium plants that tolerate brackish water, provided the specific gravity does not exceed 1.003 (around 10 percent the salinity of normal sea water).
Systematics of Vallisneria (Hydrocharitaceae)
Donald H. Les, Surrey W. L. Jacobs, Nicholas P. Tippery,1 Lei Chen, Michael L. Moody, and Maike Wilstermann-Hildebrand Systematic Botany (2008), 33(1): pp. 49–65
The canvasback (Aythya valisineria) is a species of diving duck, the largest found in North America.Eelgrass
Eelgrass is a common name for several plants and may refer to:
Zostera, marine eelgrass
Vallisneria, freshwater eelgrassEnhalus
Enhalus is a monotypic genus of marine flowering plants. The sole species is Enhalus acoroides. Enhalus is large seagrass native to coastal waters of the tropical Indian and Western Pacific Oceans. It is the only species of seagrass that does aerial surface pollination in which the pollen and the styles remain dry. Enhalus is surface pollinated with male flowers that detach from the plant to float on the surface until they reach a female flower where pollination can occur.Enhalus acoroides is considered a slow-growing, "climax" species.Freshwater aquarium
A freshwater aquarium is a receptacle that holds one or more freshwater aquatic organisms for decorative, pet-keeping, or research purposes. Modern aquariums are most often made from transparent glass or acrylic glass. Typical inhabitants include fish, plants, amphibians, and invertebrates, such as snails and crustaceans.
Freshwater fish may be either coldwater or tropical species. Although freshwater aquariums can be set up as community tanks, coldwater and tropical fish are generally not mixed due to incompatibilities in temperature requirements. Coldwater aquariums house goldfish and other species that do not require a heating apparatus. Warmer temperatures would actually increase their metabolism and shorten their lifespan. For a tropical fish tank, maintaining a warm environmental temperature ranging between 75 and 80 °F (24 to 27 °C) enables the fish to thrive.Aquariums may be decorated with sand or gravel, live or plastic plants, driftwood, rocks, and a variety of commercially made plastic sculptures. The smallest aquariums are fish bowls, but these are not recommended for most fish as they are generally too small, tend to stunt fish growth, and may lead to eventual death.Giant haplochromis
The giant haplochromis (Hemitilapia oxyrhyncha) is a species of cichlid endemic to Lake Malawi and Lake Malombe, preferring areas with sandy substrates and Vallisneria patches. It is an algae eater, obtaining its food by scraping it from the leaves of aquatic plants. This species grows to a length of 20 centimetres (7.9 in) TL. This fish can also be found in the aquarium trade. This species is the only known member of its genus.Herold Georg Wilhelm Johannes Schweickerdt
Herold Georg Wilhelm Johannes Schweickerdt (28 February 1903, Schmie, Baden-Württemberg – 21 February 1977, Pretoria) was a German botanist.
In 1904 he moved with his parents to Pretoria, where he later studied at Transvaal University. From 1922 to 1924 he was a student at the University of Bonn (1922–24), later becoming a professor in Pretoria. From 1940 to 1964 he served as inspector of the Botanical Garden at the University of Göttingen.During his career he collected plants in Transvaal, South-West Africa, Rhodesia, Mozambique and Natal. The plant species Gasteria schweickerdtiana is named after him.
The H.G.W.J Schweickerdt Herbarium (PRU) at the University of Pretoria is named in his honour.Hydrocharitaceae
Hydrocharitaceae is a flowering plant family including 16 known genera with a total of ca 135 known species (Christenhusz & Byng 2016 ), that including a number of species of aquatic plant, for instance the tape-grasses, the well known Canadian waterweed and frogbit Hydrocharis morsus-ranae.
The family includes both fresh water and marine aquatics. They are found throughout the world in a wide variety of habitats, but are primarily tropical.Lethrinops macrophthalmus
Lethrinops macrophthalmus is a species of cichlid endemic to Lake Malawi where it is known to occur in the Nkhotakota area. It prefers habitats with patches of Vallisneria. This species grows to a length of 12 centimetres (4.7 in) SL.List of freshwater aquarium plant species
Aquatic plants are used to give the freshwater aquarium a natural appearance, oxygenate the water, absorb ammonia, and provide habitat for fish, especially fry (babies) and for invertebrates. Some aquarium fish and invertebrates also eat live plants. Hobbyists use aquatic plants for aquascaping, of several aesthetic styles.
Most of these plant species are found either partially or fully submerged in their natural habitat. Although there are a handful of obligate aquatic plants that must be grown entirely underwater, most can grow fully emersed if the soil is moist. Though some are just living at the water margins, still, they can live in the completely submerged habitat.Mylochromis melanotaenia
Mylochromis melanotaenia is a species of cichlid endemic to Lake Malawi where it is believed to occur only in the southern portion of the lake. It prefers sandy substrates with patches of Vallisneria. This species can reach a length of 20 centimetres (7.9 in) TL. This species can also be found in the aquarium trade.Parapoynx obscuralis
Parapoynx obscuralis, the obscure pondweed moth, American china-mark or vallisneria leafcutter, is a moth in the Crambidae family. It was described by Augustus Radcliffe Grote in 1881. It is found in North America, where it has been recorded from Nova Scotia to Florida, west to Texas and north to Wisconsin and Ontario. It is also found in Great Britain, where it is naturalised in aquatic nurseries through accidental introduction.The wingspan is 17–26 mm. The forewings of the males are white with brown shading and a thick white postmedian line. The females have dark brown forewings. The hindwings are white with a brown or blackish band and an orange terminal band. Adults are on wing from June to August.
The larvae are aquatic and feed on various aquatic plants, including Vallisneria, Potamogeton and Nuphar species.Pioneer species
The Pioneer species are hardy species which are the first to colonize previously biodiverse steady-state ecosystems. Some lichens grow on rocks without soil, so may be among the first of life forms, and break down the rocks into soil for plants. Since some uncolonized land may have thin, poor quality soils with few nutrients, pioneer species are often hardy plants with adaptations such as long roots, root nodes containing nitrogen-fixing bacteria, and leaves that employ transpiration. Note that they are often photosynthetic plants, as no other source of energy (such as other species) except light energy is often available in the early stages of succession, thus making it less likely for a pioneer species to be non-photosynthetic. The plants that are often pioneer species also tend to be wind-pollinated rather than insect-pollinated, as insects are unlikely to be present in the usually barren conditions in which pioneer species grow; however, pioneer species tend to reproduce asexually altogether, as the extreme or barren conditions present make it more favourable to reproduce asexually in order to increase reproductive success rather than invest energy into sexual reproduction. Pioneer species will die creating plant litter, and break down as "leaf mold" after some time, making new soil for secondary succession (see below), and nutrients for small fish and aquatic plants in adjacent bodies of water.
Examples of the plants and organisms that colonize such areas are pioneer species:
Barren sand - lyme grass (Leymus arenarius), sea couch grass (Agropyron pungens), Marram grass (Ammophila breviligulata)
Salt water - green algae, marine eel grass (Zostera spp.), pickleweed (Salicornia virginica), and cordgrass (hybrid Spartina × townsendii) and (Spartina anglica).
Clear water - algae, mosses, freshwater eel grass (Vallisneria americana).
Solidified lava flows - in Hawaii: swordfern (Polystichum munitum), ‘ōhi‘a lehua (Metrosideros polymorpha), ‘ohelo (Vaccinium reticulatum) and ‘āma‘u (Sadleria cyatheoides); on Surtsey: lichen (Stereocaulon vesuvianum and Placopsis gelida) and moss (Racomitrium ericoides); green algae
Disturbed areas such as construction sites, road cuttings and verges, cultivated lands - Buddleia davidii, Nettles, Tagetes minuta, Bidens pilosa, Argemone mexicana
Bare clay - Orchids
Mountains - LichensProtomelas macrodon
Protomelas macrodon is a species of cichlid endemic to Lake Malawi where it is only known from areas vegetated with Vallisneria. This species can reach a length of 8.8 centimetres (3.5 in) SL.Trematocranus placodon
Trematocranus placodon is a species of cichlid fish endemic to Lake Malawi, Lake Malombe and the upper reaches of the Shire River in Africa. It is mainly a shallow-water species that prefers to occupy areas with patches of Vallisneria, but it can occur as deep as 31 m (102 ft). It can reach a total length of up to 25 cm (9.8 in).It feeds mainly on aquatic snails and has a preference for Bulinus nyassanus, making this cichlid beneficial to humans as that snail is an intermediate host of the parasite bilharzia (schistosomiasis). It has been suggested that an increase in bilharzia in Lake Malawi has been caused by overfishing of this and other snail-eating cichlids. It is mainly caught as a food fish, but also for the aquarium trade. Although it has seriously declined in some regions, overall it remains widespread and it is considered a species of least concern by the IUCN.Tropheops lucerna
Tropheops lucerna is a species of cichlid endemic to Lake Malawi where it is found at depths of from 2 to 4 metres (6.6 to 13.1 ft) in beds of Vallisneria in bays. This species can reach a length of 13.5 centimetres (5.3 in) TL. It can also be found in the aquarium trade. It feeds by brushing loose strands of algae off of rocks, sand and the leaves of macrophytes.V. gigantea
V. gigantea may refer to:
Vallisneria gigantea, the eelgrass, an aquatic plant species in the genus Vallisneria
Vriesea gigantea, a plant species endemic to BrazilVallisneria americana
Vallisneria americana, commonly called wild celery, water-celery, tape grass, or eelgrass, is a plant in the family Hydrocharitaceae, the "tape-grasses". V. americana is a fresh water species that can tolerate salt, living in salinities varying from fresh water (0 parts per thousand) to 18 parts per thousand, although the limit to the salt tolerance is unclear, and is generally dependent on the duration and intensity of the plants exposure to the saline water. V. americana is a deep rooted plant with leaves, approximately one inch wide, with the ability to rise two or more meters above the clustered base of the plant. Contrary to the implications of one of its common names, wild celery bears little to no resemblance to the celery used as a vegetable. Vallisneria americana grows under water and is consumed by various animals, including the canvasback. The plants themselves are long, limp, flat, and have a green mid-ridge.
Despite its name, it is not restricted to the Americas. It occurs naturally in Iraq, China, Japan, Korea, India, Papua New Guinea, the Philippines, Australia, Canada, the United States, Mexico, Guatemala, Honduras, Cuba, the Dominican Republic, Haiti and Venezuela. It is found primarily in eastern North America, occurring west from Nova Scotia to South Dakota and South to the Gulf of Mexico. It has also been reported in the western states of Washington, Nebraska, New Mexico and Arizona.Vallisneria americana is cultivated for the aquarium trade, where it is a sold as a background plant.Vallisneria spiralis
Vallisneria spiralis, also known as straight vallisneria, tape grass, or eel grass is a common aquarium plant that prefers good light and a nutrient rich substrate. In the wild, it can be found in tropical and sub-tropical regions worldwide. It has narrow, linear leaves that range in colour from a pale-green to reddish up to 3 feet (1 m) long and up to 0.75 inches broad. V. spiralis is monoecious with flowers carried on long spiral stalks that break away from the plant and float on the water's surface. Seeds have not been observed germinating in aquaria. Instead, it most often propagates by runners which can lead to dense stands.
One form of this plant has been described: V. spiralis f. tortifolia, which has also been elevated to the species level by some taxonomists under the name V. tortissima. The form has tightly twisted leaves. Along with this form, many other trade names have been developed for small variations on the species. Their taxonomic status is uncertain.Wild celery
Wild celery is a common name for several plants. It can refer to:
Wild growing forms of celery, Apium graveolens
Angelica archangelica, cultivated as a vegetable and medicinal plant
Lovage, Levisticum officinale, sometimes known as wild celery
Trachyspermum roxburghianum, a plant used as a spice in South and Southeast Asia
Vallisneria americana, an aquatic plant in the Hydrocharitaceae family