Vallisneria
Encyclopedia
Vallisneria is a genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of freshwater
Freshwater
Fresh water is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Fresh water is generally characterized by having low concentrations of dissolved salts and...

 aquatic plant
Aquatic plant
Aquatic plants are plants that have adapted to living in aquatic environments. They are also referred to as hydrophytes or aquatic macrophytes. These plants require special adaptations for living submerged in water, or at the water's surface. Aquatic plants can only grow in water or in soil that is...

, commonly called eelgrass, tape grass or vallis. The genus has 6-10 species that are widely distributed, but do not grow in colder regions.

Vallisneria is a submersed plant that spreads by runners
Vegetative reproduction
Vegetative reproduction is a form of asexual reproduction in plants. It is a process by which new individuals arise without production of seeds or spores...

 and sometimes forms tall underwater meadows. Leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....

 arise in clusters from their root
Root
In vascular plants, the root is the organ of a plant that typically lies below the surface of the soil. This is not always the case, however, since a root can also be aerial or aerating . Furthermore, a stem normally occurring below ground is not exceptional either...

s. The leaves have rounded tips, and definite raised veins. Single white female flower
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants . The biological function of a flower is to effect reproduction, usually by providing a mechanism for the union of sperm with eggs...

s grow to the water surface on very long stalks. Tape grass fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...

 is a banana
Banana
Banana is the common name for herbaceous plants of the genus Musa and for the fruit they produce. Bananas come in a variety of sizes and colors when ripe, including yellow, purple, and red....

-like capsule having many tiny seeds.

Sometimes it is confused with the superficially similar Sagittaria
Sagittaria
Sagittaria is a genus of about 30 species of aquatic plants whose members go by a variety of common names, including arrowhead, duck potato, iz-ze-kn, katniss, kuwai , swan potato, tule potato, and wapato...

 when grown submerged.

This plant should not be confused with Zostera
Zostera
Zostera is a small genus of widely distributed seagrass, commonly called marine eelgrass or simply eelgrass . The genus Zostera contains sixteen species.-Ecology:Zostera is found on sandy substrates or in estuaries submerged or partially floating...

species, marine seagrass
Seagrass
Seagrasses are flowering plants from one of four plant families , all in the order Alismatales , which grow in marine, fully saline environments.-Ecology:...

es that are usually also given the common name "eelgrass".

Use in aquaria

Various strains of Vallisneria are commonly kept in tropical and subtropical aquaria
Aquaria
Aquaria may refer to:*Aquarium, in the plural*Aquaria , a computer game*Aquaria , a Brazilian metal band*Aquaria, one of the Twelve Colonies in Battlestar Galactica...

.
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. 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
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...

 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).

Species

  • Vallisneria aethiopica
  • Vallisneria americana
    Wild celery
    Wild celery is a plant in the family Hydrocharitaceae . Contrary to the implications of its name, wild celery bears little to no resemblance to the celery used as a vegetable. Wild celery grows under water and is consumed by various animals, including the canvasback...

  • Vallisneria alternifolia
  • Vallisneria anhuiensis
  • Vallisneria asiatica
  • Vallisneria natans
  • Vallisneria spiralis
    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...

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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