''Alisma lanceolatum'' is a species of

aquatic plant Aquatic plants, also referred to as hydrophytes, are vascular plants and Non-vascular plant, non-vascular plants that have adapted to live in aquatic ecosystem, aquatic environments (marine ecosystem, saltwater or freshwater ecosystem, freshwater ...

in the water plantain family known by the common names lanceleaf water plantain and narrow-leaved water plantain. It is widespread across

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

North Africa North Africa (sometimes Northern Africa) is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region. However, it is sometimes defined as stretching from the Atlantic shores of t ...

and temperate

Asia Asia ( , ) is the largest continent in the world by both land area and population. It covers an area of more than 44 million square kilometres, about 30% of Earth's total land area and 8% of Earth's total surface area. The continent, which ...

. It is naturalized in

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

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 ...

Oregon Oregon ( , ) is a U.S. state, state in the Pacific Northwest region of the United States. It is a part of the Western U.S., with the Columbia River delineating much of Oregon's northern boundary with Washington (state), Washington, while t ...

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

and

British Columbia British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...

. It is considered a

noxious weed A noxious weed, harmful weed or injurious weed is a weed that has been designated by an agricultural or other governing authority as a plant that is harmful to agricultural or horticultural crops, natural habitats or ecosystems, or humans or lives ...

in some places. This species is a weed of rice fields in many areas, including

New South Wales New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...

and

. In

England England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It ...

and

Wales Wales ( ) is a Countries of the United Kingdom, country that is part of the United Kingdom. It is bordered by the Irish Sea to the north and west, England to the England–Wales border, east, the Bristol Channel to the south, and the Celtic ...

it is occasionally locally found, in

Ireland Ireland (, ; ; Ulster Scots dialect, Ulster-Scots: ) is an island in the North Atlantic Ocean, in Northwestern Europe. Geopolitically, the island is divided between the Republic of Ireland (officially Names of the Irish state, named Irelan ...

it is rare, and

Scotland Scotland is a Countries of the United Kingdom, country that is part of the United Kingdom. It contains nearly one-third of the United Kingdom's land area, consisting of the northern part of the island of Great Britain and more than 790 adjac ...

it is very rare. It is found in mud and in fresh waters.

Description

This is a

perennial herb In horticulture, the term perennial ('' per-'' + '' -ennial'', "through the year") is used to differentiate a plant from shorter-lived annuals and biennials. It has thus been defined as a plant that lives more than 2 years. The term is also ...

growing from a

caudex A caudex (: caudices) of a plant is a stem, but the term is also used to mean a rootstock and particularly a basal stem structure from which new growth arises.pages 456 and 695 In the strict sense of the term, meaning a stem, "caudex" is most ...

in the water or mud that typically reaches a height of about 0.7 meters and a spread of 0.25 meters. It produces lance-shaped

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, ...

12 to 20 centimeters long and 4 wide on long petioles; leaves which remain submerged in water are smaller and less prominently veined. 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 branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

is mostly erect and up to half a meter tall. It produces a wide array of small pinkish-purple three-petalled

flower Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...

s that open in the morning, from June until August. The

fruit In botany, a fruit is the seed-bearing structure in flowering plants (angiosperms) that is formed from the ovary after flowering. Fruits are the means by which angiosperms disseminate their seeds. Edible fruits in particular have long propaga ...

is a tiny

achene An achene (; ), also sometimes called akene and occasionally achenium or achenocarp, is a type of simple fruit, simple dry fruits, dry fruit produced by many species of flowering plants. Achenes are monocarpellate (formed from one carpel) and Dehi ...

up to 2 or 3 millimeters long clustered into an aggregate fruit of about 20 units. The

seed In botany, a seed is a plant structure containing an embryo and stored nutrients in a protective coat called a ''testa''. More generally, the term "seed" means anything that can be Sowing, sown, which may include seed and husk or tuber. Seeds ...

s are reddish-brown and about 1.5 millimeters long.

Cultivation

Grows best in water 15-30 centimeters deep in full sun. Suitable for

USDA hardiness zones A hardiness zone is a geographic area defined as having a certain average annual minimum temperature, a factor relevant to the survival of many plants. In some systems other statistics are included in the calculations. The original and most widely ...

5–8.

Similar Species

The water plantain ''

Alisma plantago-aquatica ''Alisma plantago-aquatica'', also known as European water-plantain, common water-plantain or mad-dog weed, is a perennial flowering plant, flowering aquatic plant widespread across most of Europe and Asia, and apparently spread elsewhere in both ...

'' has acute leaf tips not tapering to a stalk. The flowers of A. plantago-aquatica also typically open in the afternoon, and the leaves are wider.

References

External links

Jepson Manual TreatmentWeeds Australia ''Alisma lanceolatum''Calflora taxon report ''Alisma lanceolatum''Altervista Flora Italiana, Mestolaccia lanceolata, ''Alisma lanceolatum''Flore Alpes, Alisma lancéolé, ''Alisma lanceolatum''Le Jardin du Pic Vert, Plantain d'eau à feuilles lancéolées, ''Alisma lanceolatum''Flora On Portugal, ''Alisma lanceolatum''New Zealand Plant Conservation Network, ''Alisma lanceolatum''
{{Taxonbar, from=Q1788480 lanceolatum Freshwater plants Plants described in 1796 Flora of the Canary Islands Flora of Switzerland Flora of Portugal Flora of Russia Flora of Central Asia Flora of Siberia Flora of China Flora of Asia Flora of Europe Flora of Australia Flora of New Zealand Flora of California Flora of British Columbia