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

aquarium An aquarium (plural: ''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. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aq ...

plant that prefers good light and a nutrient rich substrate. In the wild, it can be found in tropical and sub-tropical regions worldwide.

Overview

It has narrow,

linear Linearity is the property of a mathematical relationship ('' function'') that can be graphically represented as a straight line. Linearity is closely related to '' proportionality''. Examples in physics include rectilinear motion, the linear ...

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

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 alongside gynomonoecy, andromonoecy and trimonoecy. Monoecy is ...

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. Such inflorescences are described as ''pedicellate''. Description Pedicel refers to a structure connecting a single flower to its inflorescence. In the absenc ...

) 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, most often by an animal or by wind. Pollinating agents can be animals such as insects, birds, a ...

, the pedicel curls up like a

tendril In botany, a tendril is a specialized stem, leaf or petiole with a threadlike shape used by climbing plants for support and attachment, as well as cellular invasion by parasitic plants such as '' Cuscuta''. There are many plants that have tend ...

, 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 also refers to: *Form (document), a document (printed or electronic) with spaces in which to write or enter data * ...

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 ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island coun ...

. 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 coun ...

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

Iceland Iceland ( is, Ísland; ) is a Nordic island country in the North Atlantic Ocean and in the Arctic Ocean. Iceland is the most sparsely populated country in Europe. Iceland's capital and largest city is Reykjavík, which (along with its ...

, where it was recorded in geothermal ponds.

References

External links

AquaHobby

AquaHobby ''var. tortissima''

Tropica spiralis 'Tiger'

Plants for a Future
{{Taxonbar, from=Q159160 Hydrocharitaceae Freshwater plants Plants described in 1753 Taxa named by Carl Linnaeus