''Vallisneria spiralis'', also known as straight vallisneria, tape grass, or eel grass is a common

aquarium An aquarium (: aquariums or aquaria) is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. fishkeeping, Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aquati ...

plant that prefers good light and a nutrient rich

substrate Substrate may refer to: Physical layers *Substrate (biology), the natural environment in which an organism lives, or the surface or medium on which an organism grows or is attached ** Substrate (aquatic environment), the earthy material that exi ...

. In the wild, it can be found in tropical and sub-tropical regions worldwide.

Overview

It has narrow,

linear In mathematics, the term ''linear'' is used in two distinct senses for two different properties: * linearity of a '' function'' (or '' mapping''); * linearity of a '' polynomial''. An example of a linear function is the function defined by f(x) ...

leaves A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...

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 Monoecy (; adj. monoecious ) is a sexual system in seed plants where separate male and female cones or flowers are present on the same plant. It is a monomorphic sexual system comparable with gynomonoecy, andromonoecy and trimonoecy, and contras ...

with male flowers carried on long spiral stalks that break away from the plant and float on the water's surface. In the variety ''V.s, gigantea'' the female flowers are on stalks (

pedicels In botany, a pedicel is a stem that attaches a single flower to the inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branch ...

) up to six feet (1.85 meters) in length. After the female flowers have been

pollinated Pollination is the transfer of pollen from an anther of a plant to the stigma of a plant, later enabling fertilisation and the production of seeds. Pollinating agents can be animals such as insects, for example bees, beetles or butterflies; bird ...

, the pedicel curls up like a

tendril In botany, a tendril is a specialized Plant stem, stem, leaf or Petiole (botany), petiole with a thread-like shape used by climbing plants for support and attachment, as well as cellular invasion by parasitic plants such as ''Cuscuta''. There ar ...

, drawing the young fruit closer to the bed of the stream or pond; thus the name "spiralis". Seeds have not been observed germinating in aquaria. Instead, it most often propagates by runners which can lead to dense stands. 1856aquariumfresh

One

form Form is the shape, visual appearance, or configuration of an object. In a wider sense, the form is the way something happens. Form may also refer to: *Form (document), a document (printed or electronic) with spaces in which to write or enter dat ...

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.

Invasive species

The species is an effective invader due to its efficient dispersal, vegetative reproduction, high biomass production, and popularity in the aquarium trade. ''V. spiralis'' is an "unwanted organism" in

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

. It is listed on the

National Pest Plant Accord The National Pest Plant Accord (NPPA) is a New Zealand agreement that identifies pest plants that are prohibited from sale and commercial propagation and distribution. The Accord initially came into effect on 1 October 2001 between regional cou ...

prohibiting it from sale and commercial propagation and distribution. Since 2013 ''V. spiralis'' has been listed as a naturalized alien in

Iceland Iceland is a Nordic countries, Nordic island country between the Atlantic Ocean, North Atlantic and Arctic Oceans, on the Mid-Atlantic Ridge between North America and Europe. It is culturally and politically linked with Europe and is the regi ...

, where it was recorded in geothermal ponds.

References

External links

AquaHobby

AquaHobby ''var. tortissima''

Tropica spiralis 'Tiger'

Plants for a Future
Hydrocharitaceae Freshwater plants Plants described in 1753 Taxa named by Carl Linnaeus {{alismatales-stub