''Echinodorus'', commonly known as burhead or Amazon sword, is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of plants in the family

Alismataceae The water-plantains (Alismataceae) are a family of flowering plants, comprising 20 genera (17 extant and 3 fossil) and 119 species. The family has a cosmopolitan distribution, with the greatest number of species in temperate regions of the Northe ...

, native to the

Western Hemisphere The Western Hemisphere is the half of the planet Earth that lies west of the Prime Meridian (which crosses Greenwich, London, United Kingdom) and east of the 180th meridian.- The other half is called the Eastern Hemisphere. Geopolitically, ...

from the central United States to Argentina. Its

scientific name In Taxonomy (biology), taxonomy, binomial nomenclature ("two-term naming system"), also called binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, both of which use Latin gramm ...

is derived from

Ancient Greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...

' – "rough husk" - and ' – "leathern bottle" - alluding to ovaries, which in some species are armed with persistent styles, forming prickly head of fruit. Some of the species are commonly cultivated in artificial aquatic habitats.

Description

The plants are

annual Annual may refer to: *Annual publication, periodical publications appearing regularly once per year **Yearbook **Literary annual *Annual plant *Annual report *Annual giving *Annual, Morocco, a settlement in northeastern Morocco *Annuals (band), a ...

perennial 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 emersed, floating-leaved, or seasonally submersed, leaves

glabrous Glabrousness () is the technical term for a lack of hair, down, setae, trichomes, or other such covering. A glabrous surface may be a natural characteristic of all or part of a plant or animal, or be due to loss because of a physical condition, ...

to stellate-pubescent;

rhizomes In botany and dendrology, a rhizome ( ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow hori ...

present or absent;

stolons In biology, a stolon ( from Latin '' stolō'', genitive ''stolōnis'' – "branch"), also known as a runner, is a horizontal connection between parts of an organism. It may be part of the organism, or of its skeleton. Typically, animal stolons ar ...

absent;

corm Corm, bulbo-tuber, or bulbotuber is a short, vertical, swollen, underground plant stem that serves as a storage organ that some plants use to survive winter or other adverse conditions such as summer drought and heat (perennation). The word ''c ...

s absent;

tubers Tubers are a type of enlarged structure that plants use as storage organs for nutrients, derived from stems or roots. Tubers help plants perennate (survive winter or dry months), provide energy and nutrients, and are a means of asexual reprod ...

absent.

Root In vascular plants, the roots are the plant organ, organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often bel ...

s not septate. Leaves

sessile Sessility, or sessile, may refer to: * Sessility (motility), organisms which are not able to move about * Sessility (botany), flowers or leaves that grow directly from the stem or peduncle of a plant * Sessility (medicine), tumors and polyps that ...

or petiolate; petioles triangular, rarely terete; blade with translucent markings as dots or lines present or absent, linear to lanceolate to ovate, base attenuate to cordate, margins entire or undulating, apex obtuse to acute.

Inflorescences In botany, an inflorescence is a group or cluster of flowers arranged on a plant's 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 main axis ( pe ...

racemes A raceme () or racemoid is an unbranched, indeterminate type of inflorescence bearing flowers having short floral stalks along the shoots that bear the flowers. The oldest flowers grow close to the base and new flowers are produced as the shoo ...

panicles In botany, a panicle is a much-branched inflorescence. (softcover ). Some authors distinguish it from a compound spike inflorescence, by requiring that the flowers (and fruit) be pedicellate (having a single stem per flower). The branches of a p ...

, rarely umbels, of 1–18 whorls, erect or decumbent, emersed;

bracts In botany, a bract is a modified or specialized leaf, associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves in size, color, shape or texture. They also loo ...

coarse, apex obtuse to acute, surfaces smooth or papillose along veins, apex obtuse to acute.

Flowers 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 ...

bisexual, subsessile to pedicellate;

subtending pedicels, subulate to lanceolate, shorter than to longer than pedicels, apex obtuse to acute; pedicels ascending to recurved; receptacle convex;

sepals A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 Etymology The term ''sepalum'' ...

recurved to spreading,

herbaceous Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials. Definitions of "herb" and "herbaceous" The fourth edition of ...

to leathery, sculpturing absent;

petals Petals are modified leaves that form an inner whorl surrounding the reproductive parts of flowers. They are often brightly coloured or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''coroll ...

white, entire;

stamens The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filamen ...

9–25; filaments linear, glabrous; pistils 15–250 or more, spirally arranged on convex receptacle, forming head, distinct;

ovules In seed plants, the ovule is the structure that gives rise to and contains the female reproductive cells. It consists of three parts: the ''integument'', forming its outer layer, the ''nucellus'' (or remnant of the megasporangium), and the fe ...

1; style terminal or lateral.

Fruits 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 ...

plump, often longitudinally ribbed, sometimes flattened, rarely abaxially keeled, abaxial wings absent, lateral wings absent, glands often present.

Cultivation

''Echinodorus'' are by nature marsh and bog plants that can grow submersed. Many species are grown in

aquariums 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 ...

. They prefer good light and grow best in a deep, 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 ...

. Most will grow in variable water conditions, though the majority need tropical or

sub-tropical The subtropical zones or subtropics are geographical and climate zones immediately to the north and south of the tropics. Geographically part of the temperate zones of both hemispheres, they cover the middle latitudes from to approximately 3 ...

temperature ranges. Propagation is by division or by adventitious new plants developing on submerged flowering stems. The larger species make magnificent specimen plants for the larger aquarium, though they may form aerial leaves in good conditions. If 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 ...

forms submersed, small plantlets will form instead of flowers. If grown emersed and kept humid, flowers and seeds will normally readily form. The seeds can be grown in damp sand in warm, damp conditions. Additional CO₂ often helps in strong growth. Many species are popular in the

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 ...

pond A pond is a small, still, land-based body of water formed by pooling inside a depression (geology), depression, either naturally or artificiality, artificially. A pond is smaller than a lake and there are no official criteria distinguishing ...

. The Amazon sword plants are one of the most popular

plants for their attractive form and general hardiness. A submerged culture system was developed for rapid micropropagation of this commercially important aquarium plant, ‘Amazon sword’ (''Echinodorus'' ‘Indian Red’).

Taxonomy

The genus ''Baldellia'' seems to be very closely related. In the latest revision by

Karel Rataj Karel may refer to: People * Karel (given name) * Karel (surname) * Charles Karel Bouley (born 1962), American talk radio personality known on air as Karel * Christiaan Karel Appel (1921–2006), Dutch painter and sculptor Business * Karel Elec ...

, 62 species, 2 subspecies, and 2 varieties are listed. All

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of Echinodorus are variable according to whether they are growing emersed or submerged and their growing conditions. In addition they can hybridise in the wild or through artificial means. Many forms have been given subspecific status or as named forms in the

trade. According to aquarists some of these forms persist in all growing conditions.

Species

As of May 2014, 30 species are accepted by authorities at Kew Royal Botanic Gardens:Kew World Checklist of Selected Plant Families
/ref> Included in the list below are names accepted in previous versions but now regarded as synonyms. #'' Echinodorus angustifolius'' Rataj - syn of '' Helanthium bolivianum'' (Rusby) Lehtonen & Myllys #'' Echinodorus argentinensis'' Rataj - syn of '' Echinodorus grandiflorus'' (Cham. & Schltdl.) Micheli #'' Echinodorus aschersonianus'' Graebn. - syn of '' Echinodorus uruguayensis'' Arechav #'' Echinodorus berteroi'' (Spreng.) Fassett - from

South Dakota South Dakota (; Sioux language, Sioux: , ) is a U.S. state, state in the West North Central states, North Central region of the United States. It is also part of the Great Plains. South Dakota is named after the Dakota people, Dakota Sioux ...

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

#'' Echinodorus bleherae'' or '' E. bleheri'' Rataj - syn of ''

Echinodorus grisebachii ''Echinodorus grisebachii'' or ''Echinodorus amazonicus'' is commonly known as Amazon sword plant, although other plants are also known under this common name. The aquatic plant is cultivated for and used in ponds and artificial aquatic habitats. ...

'' Small #'' Echinodorus bracteatus'' Micheli - from

Nicaragua Nicaragua, officially the Republic of Nicaragua, is the geographically largest Sovereign state, country in Central America, comprising . With a population of 7,142,529 as of 2024, it is the third-most populous country in Central America aft ...

Ecuador Ecuador, officially the Republic of Ecuador, is a country in northwestern South America, bordered by Colombia on the north, Peru on the east and south, and the Pacific Ocean on the west. It also includes the Galápagos Province which contain ...

#''

Echinodorus cordifolius ''Echinodorus'', commonly known as burhead or Amazon sword, is a genus of plants in the family Alismataceae, native to the Western Hemisphere from the central United States to Argentina. Its scientific name is derived from Ancient Greek ' – "r ...

'' (L.) Griseb. - from

Illinois Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. It borders on Lake Michigan to its northeast, the Mississippi River to its west, and the Wabash River, Wabash and Ohio River, Ohio rivers to its ...

Paraguay Paraguay, officially the Republic of Paraguay, is a landlocked country in South America. It is bordered by Argentina to the Argentina–Paraguay border, south and southwest, Brazil to the Brazil–Paraguay border, east and northeast, and Boli ...

#'' Echinodorus cylindricus'' Rataj -

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

#'' Echinodorus decumbens'' Kasselm. -

#'' Echinodorus densinervis'' Somogyi -

#'' Echinodorus eglandulosus'' Rataj -

#'' Echinodorus emersus'' Lehtonen -

Peru Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...

Bolivia Bolivia, officially the Plurinational State of Bolivia, is a landlocked country located in central South America. The country features diverse geography, including vast Amazonian plains, tropical lowlands, mountains, the Gran Chaco Province, w ...

#'' Echinodorus floribundus'' (Seub.) Seub. -

Veracruz Veracruz, formally Veracruz de Ignacio de la Llave, officially the Free and Sovereign State of Veracruz de Ignacio de la Llave, is one of the 31 states which, along with Mexico City, comprise the 32 Political divisions of Mexico, Federal Entit ...

#'' Echinodorus gabrielii'' Rataj -

#'' Echinodorus glaucus'' Rataj -

#'' Echinodorus grandiflorus'' (Cham. & Schltdl.) Micheli -

Uruguay Uruguay, officially the Oriental Republic of Uruguay, is a country in South America. It shares borders with Argentina to its west and southwest and Brazil to its north and northeast, while bordering the Río de la Plata to the south and the A ...

Venezuela Venezuela, officially the Bolivarian Republic of Venezuela, is a country on the northern coast of South America, consisting of a continental landmass and many Federal Dependencies of Venezuela, islands and islets in the Caribbean Sea. It com ...

Florida Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...

#''

'' Small - from

#'' Echinodorus heikobleheri'' Rataj -

#'' Echinodorus horizontalis'' Rataj - from

Guyana Guyana, officially the Co-operative Republic of Guyana, is a country on the northern coast of South America, part of the historic British West Indies. entry "Guyana" Georgetown, Guyana, Georgetown is the capital of Guyana and is also the co ...

#'' Echinodorus inpai'' Rataj -

#'' Echinodorus isthmicus'' Fassett - syn of '' Helanthium bolivianum'' (Rusby) Lehtonen & Myllys #'' Echinodorus lanceolatus'' Rataj -

#'' Echinodorus longipetalus'' Micheli - from

Suriname Suriname, officially the Republic of Suriname, is a country in northern South America, also considered as part of the Caribbean and the West Indies. It is a developing country with a Human Development Index, high level of human development; i ...

#'' Echinodorus longiscapus'' Arechav. -

#'' Echinodorus macrocarpus'' Rataj - syn of '' Echinodorus pubescens'' (Mart. ex Schult.f.) Seub. ex Warm. -

#'' Echinodorus macrophyllus'' (Kunth) Micheli -

#'' Echinodorus major'' (Micheli) Rataj -

#'' Echinodorus nymphaeifolius'' (Griseb.) Buchenau - syn of '' Albidella nymphaeifolia'' (Griseb.) Pichon #''

Echinodorus opacus ''Echinodorus uruguayensis'' is a plant species in the Alismataceae. It is native to South America (Brazil, Argentina, Paraguay, Uruguay, Chile). Description Submersed leaves (5)-30-50 cm long, blades ribbon-shaped, green or darkly red-brow ...

'' Rataj - syn of '' Echinodorus uruguayensis'' Arechav #'' Echinodorus osiris'' Rataj - syn of '' Echinodorus uruguayensis'' Arechav #'' Echinodorus ovalis'' C.Wright - syn of ''

'' (L.) Griseb #'' Echinodorus palaefolius'' (Nees & Mart.) J.F.Macbr. -

Nayarit Nayarit, officially the Free and Sovereign State of Nayarit, is one of the 31 states that, along with Mexico City, comprise the Political divisions of Mexico, Federal Entities of Mexico. It is divided in Municipalities of Nayarit, 20 municipalit ...

Minas Gerais Minas Gerais () is one of the 27 federative units of Brazil, being the fourth largest state by area and the second largest in number of inhabitants with a population of 20,539,989 according to the 2022 Brazilian census, 2022 census. Located in ...

#'' Echinodorus paniculatus'' Micheli in A.L.P.de Candolle & A.C.P.de Candolle - from

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

#'' Echinodorus reptilis'' Lehtonen -

#'' Echinodorus scaber'' Rataj - from

#'' Echinodorus subalatus'' (Mart. ex Schult.f.) Griseb. - from

; also

Cuba Cuba, officially the Republic of Cuba, is an island country, comprising the island of Cuba (largest island), Isla de la Juventud, and List of islands of Cuba, 4,195 islands, islets and cays surrounding the main island. It is located where the ...

#'' Echinodorus tenellus'' (Mart. ex Schult.f.) Buchenau - syn of '' Helanthium tenellum'' (Mart. ex Schult.f.) J.G.Sm. in N.L.Britton #'' Echinodorus trialatus'' Fassett -

Panama Panama, officially the Republic of Panama, is a country in Latin America at the southern end of Central America, bordering South America. It is bordered by Costa Rica to the west, Colombia to the southeast, the Caribbean Sea to the north, and ...

Colombia Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...

#'' Echinodorus tunicatus'' Small - from

Costa Rica Costa Rica, officially the Republic of Costa Rica, is a country in Central America. It borders Nicaragua to the north, the Caribbean Sea to the northeast, Panama to the southeast, and the Pacific Ocean to the southwest, as well as Maritime bo ...

#'' Echinodorus uruguayensis'' Arechav. -

Chile Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Paci ...

#'' Echinodorus virgatus'' (Hook. & Arn.) Micheli - syn of '' Echinodorus palifolius'' (Nees & Mart.) J.F.Macbr

References

External links

''Echinodorus''

Shutting down the chaos engine — or, identifying some problematic Echinodorus (Alismataceae) types

Bibliography

* Lehtonen S and Myllys L. 2008. Cladistic analysis of Echinodorus (Alismataceae): simultaneous analysis of molecular and morphological data. Cladistics 24: 218–239. {{Authority control Alismataceae genera Aquatic plants