''Lythrum salicaria'' or purple loosestrifeFlora of NW Europe
''Lythrum salicaria''
is a

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Ancient Greek, Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed with ...

belonging to the family

Lythraceae Lythraceae is a family (biology), family of flowering plants, including 32 genus, genera, with about 620 species of Herbaceous plant, herbs, shrubs, and trees. The larger genera include ''Cuphea'' (275 spp.), ''Lagerstroemia'' (56), ''Nesaea (pl ...

. It should not be confused with other plants sharing the name loosestrife that are members of the family

Primulaceae The Primulaceae ( ), commonly known as the primrose family (but not related to the Onagraceae, evening primrose family), are a family (biology), family of Herbaceous plant, herbaceous and woody flowering plants including some favourite garden pla ...

. Other names include spiked loosestrife and purple Lythrum. This

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 ...

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 ...

is native to Europe and Asia, and possibly Australia.

Etymology and other names

The generic name ''Lythrum'' is derived from the Greek 'lythron', meaning blood, in reference to the flower colour in some species.Gledhill D. 1985. ''The Names of Plants''. Cambridge University Press However, Pliny (A.D. 23–79) stated that ''Lythrum'' is named for

Lysimachus Lysimachus (; Greek language, Greek: Λυσίμαχος, ''Lysimachos''; c. 360 BC – 281 BC) was a Thessaly, Thessalian officer and Diadochi, successor of Alexander the Great, who in 306 BC, became king of Thrace, Anatolia, Asia Minor and Mace ...

, an army general and friend of

Alexander the Great Alexander III of Macedon (; 20/21 July 356 BC – 10/11 June 323 BC), most commonly known as Alexander the Great, was a king of the Ancient Greece, ancient Greek kingdom of Macedonia (ancient kingdom), Macedon. He succeeded his father Philip ...

. ''Lysimachus'' is derived from the Greek ''lysis'', meaning "loosing" and ''mache'', meaning "strife". Mitich LW. 1999. ''Lythrum salicaria'' L. ''Weed Technology'' 13: 843 – 846. The

specific epithet 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 ...

''salicaria'' derives from the similarity of the leaves to those of willows or ''

Salix Willows, also called sallows and osiers, of the genus ''Salix'', comprise around 350 species (plus numerous hybrids) of typically deciduous trees and shrubs, found primarily on moist soils in cold and temperate regions. Most species are known ...

'' species. The English

calque In linguistics, a calque () or loan translation is a word or phrase borrowed from another language by literal word-for-word or root-for-root translation. When used as a verb, "to calque" means to borrow a word or phrase from another language ...

'loosestrife' first appeared in written form in the 16th century. It was coined by English naturalist William Turner in his 1548 work ''A New Herball'', in which he states: " he plantmay in englishe be called red loosestryfe or purple loosestryfe." Purple loosestrife was referred to several times as 'long purples' by

John Clare John Clare (13 July 1793 – 20 May 1864) was an English poet. The son of a farm labourer, he became known for his celebrations of the English countryside and his sorrows at its disruption. His work underwent major re-evaluation in the late 20t ...

, such as in his 1821 poem ''The Wildflower Nosegay'':

Description

''Lythrum salicaria'' can grow tall, forming

clonal colonies A clonal colony or genet is a group of genetically identical individuals, such as plants, fungi, or bacteria, that have grown in a given location, all originating vegetatively, not sexually, from a single ancestor. In plants, an individual in ...

or more in width, with numerous erect stems growing from a single woody root mass. The stems are reddish-purple and square in cross-section. The leaves are

lanceolate The following terms are used to describe leaf plant morphology, morphology in the description and taxonomy (biology), taxonomy of plants. Leaves may be simple (that is, the leaf blade or 'lamina' is undivided) or compound (that is, the leaf blade ...

, long and broad, downy and

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 ...

, and arranged opposite or in whorls of three. The flowers are reddish purple, in diameter, with six petals (occasionally five) and 12 stamens, and are clustered tightly in the

axil 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, fl ...

s of

bract 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 lo ...

s or leaves, (a type of inflorescence called a verticilaster), there are three different flower types, with the stamens and style of different lengths, short, medium or long; each flower type can only be pollinated by one of the other types, not the same type, thus ensuring cross-pollination between different plants.Blamey, M. & Grey-Wilson, C. (1989). ''The Illustrated Flora of Britain and Northern Europe''. Hodder & Stoughton. . For instance, if the

pistil Gynoecium (; ; : gynoecia) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl (botany), whorl of a flower; it consists ...

is medium length, then the

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 ...

will be long and short, but not medium. The flowers are visited by many types of insects, and can be characterized by a generalized

pollination syndrome Pollination syndromes are suites of flower traits that have evolved in response to natural selection imposed by different Pollination, pollen vectors, which can be abiotic (wind and water) or biotic, such as birds, bees, flies, and so forth thro ...

. The fruit is a small capsule containing numerous minute

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. Flowering lasts throughout the summer. When the seeds are mature, the leaves often turn bright red through dehydration in early autumn; the red colour may last for almost two weeks. The dead stalks from previous growing seasons are brown. ''L. salicaria'' is very variable in leaf shape and degree of hairiness, and a number of subspecies and varieties have been described, but it is now generally regarded as monotypic with none of these variants being considered of botanical significance. The species ''Lythrum intermedium'' Ledeb. ex Colla is also now considered

synonymous A synonym is a word, morpheme, or phrase that means precisely or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are a ...

Distribution

''Lythrum salicaria'' is native to Europe, temperate Asia and northwest Africa. It is also naturalized in many temperate parts of the world, including parts of southern Africa, North America, and South America.Med-Checklist: ''Lythrum salicaria''/ref> The species was thought to be a recent introduction to Australia, but pre-colonial pollen samples have been found in New South Wales, indicating another route of introduction; the question is considered unresolved by Australian authorities.

Ecology

Found in ditches,

wet meadow A wet meadow is a type of wetland with soils that are Solubility, saturated for part or all of the growing season which prevents the growth of trees and brush. Debate exists whether a wet meadow is a type of marsh or a completely separate type of ...

s and marshes and along sides of lakes. In North America, purple loosestrife can invade sedge meadows.

Associated insects

Bombus sylvarum - Lythrum salicaria - Keila

The flowers are pollinated by long-tongued insects, including

bee Bees are winged insects closely related to wasps and ants, known for their roles in pollination and, in the case of the best-known bee species, the western honey bee, for producing honey. Bees are a monophyletic lineage within the superfamil ...

s and

butterflies Butterflies are winged insects from the lepidopteran superfamily Papilionoidea, characterized by large, often brightly coloured wings that often fold together when at rest, and a conspicuous, fluttering flight. The oldest butterfly fossi ...

. A number of

insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...

s use ''Lythrum salicaria'' as a food resource. The black-margined loosestrife beetle '' Galerucella calmariensis'' is a brown beetle with a black line on its thorax. The adult feeds on the leaves of the plant, producing characteristic round holes. Its larvae destroy tender leaf buds and strip the tissue from the leaves. The golden loosestrife beetle '' Galerucella pusilla'' is nearly identical to ''G. calmariensis'', but usually lacks the black thoracic line. Its feeding habits are also quite similar to the other leaf beetle. The loosestrife root weevil ''

Hylobius transversovittatus ''Hylobius transversovittatus'' is a species of weevil in the family Curculionidae. It is native to the Old World where both adults and larvae feed on purple loosestrife (''Lythrum salicaria''). This plant is regarded as an invasive species in No ...

'' is a large red nocturnal weevil, which spends its nights feeding on leaves and leaf buds. The larvae emerge from their eggs and immediately burrow into the root of the plant, which they feed on continuously for over a year. This root damage stunts the plant's growth and ability to create seeds. If several larvae inhabit the same root, the plant can be killed. The loosestrife flower weevil '' Nanophyes marmoratus'' is a tiny weevil which lays a single egg in each flower. When the larvae emerge they eat the flowers' ovaries, and the plant is unable to create seeds. The larvae usually proceed to hollow out the flower buds and use them as safe places to pupate.

Caterpillar Caterpillars ( ) are the larval stage of members of the order Lepidoptera (the insect order comprising butterflies and moths). As with most common names, the application of the word is arbitrary, since the larvae of sawflies (suborder ...

s of the engrailed moth (''

Ectropis crepuscularia The engrailed and small engrailed (''Ectropis crepuscularia'') are moths of the family Geometridae found from the British Isles through central and eastern Europe to the Russian Far East and Kazakhstan. The western Mediterranean and Asia Minor ...

''), a polyphagous

geometer moth The geometer moths are moths belonging to the family Geometridae of the insect order Lepidoptera, the moths and butterflies. Their scientific name derives from the Ancient Greek (derivative form of or "the earth"), and "measure" in referen ...

, also feed on purple loosestrife.

Cultivation, uses and impact

It has been used as an

astringent An astringent (sometimes called adstringent) is a chemical that shrinks or constricts body tissues. The word derives from the Latin '' adstringere'', which means "to bind fast". Astringency, the dry, puckering or numbing mouthfeel caused by t ...

medicinal herb Medicinal plants, also called medicinal herbs, have been discovered and used in traditional medicine practices since prehistoric times. Plants synthesize hundreds of chemical compounds for various functions, including Plant defense against h ...

to treat

diarrhea Diarrhea (American English), also spelled diarrhoea or diarrhœa (British English), is the condition of having at least three loose, liquid, or watery bowel movements in a day. It often lasts for a few days and can result in dehydration d ...

and

dysentery Dysentery ( , ), historically known as the bloody flux, is a type of gastroenteritis that results in bloody diarrhea. Other symptoms may include fever, abdominal pain, and a feeling of incomplete defecation. Complications may include dehyd ...

; it is considered safe to use for all ages, including babies.Plants for a Future
''Lythrum salicaria''
/ref> It is also cultivated as an

ornamental plant Ornamental plants or ''garden plants'' are plants that are primarily grown for their beauty but also for qualities such as scent or how they shape physical space. Many flowering plants and garden varieties tend to be specially bred cultivars th ...

in gardens, and is particularly associated with damp, poorly drained locations such as marshes, bogs and watersides. However, it will tolerate drier conditions. The flowers are showy and bright, and a number of

cultivar A cultivar is a kind of Horticulture, cultivated plant that people have selected for desired phenotypic trait, traits and which retains those traits when Plant propagation, propagated. Methods used to propagate cultivars include division, root a ...

s have been selected for variation in flower colour, including: * 'Atropurpureum' with dark purple flowers * 'Brightness' with deep pink flowers * 'Happy' with red flowers on a short () stem * 'Purple Spires' with purple flowers on a tall stem * 'Roseum Superbum' with large pink flowers.Huxley, A., ed. (1992). ''New RHS Dictionary of Gardening''. Macmillan . The cultivars ‘Blush’ with blush-pink flowers, and 'Feuerkerze' with rose-red flowers have gained the

Royal Horticultural Society The Royal Horticultural Society (RHS), founded in 1804 as the Horticultural Society of London, is the UK's leading gardening charity. The RHS promotes horticulture through its five gardens at Wisley (Surrey), Hyde Hall (Essex), Harlow Carr ...

Award of Garden Merit The Award of Garden Merit (AGM) is a long-established award for plants by the British Royal Horticultural Society (RHS). It is based on assessment of the plants' performance under UK growing conditions. It includes the full range of cultivated p ...

. It has also been introduced in many areas of North America by

bee keeper Beekeeping (or apiculture, from ) is the maintenance of bee colonies, commonly in artificial beehives. Honey bees in the genus ''Apis (bee), Apis'' are the most commonly kept species but other honey producing bees such as ''Melipona'' stingless be ...

s, due to its abundance of flowers which provide an important source of

nectar Nectar is a viscous, sugar-rich liquid produced by Plant, plants in glands called nectaries, either within the flowers with which it attracts pollination, pollinating animals, or by extrafloral nectaries, which provide a nutrient source to an ...

. These reviews cite this research.

As an invasive species

Purple loosestrife has been introduced into temperate

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 ...

and

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

where it is now widely

naturalised Naturalization (or naturalisation) is the legal act or process by which a non-national of a country acquires the nationality of that country after birth. The definition of naturalization by the International Organization for Migration of the ...

(spreading on its own) and officially listed in some controlling agents. Infestations may rarely result in dramatic disruption in water flow in rivers and canals, and the life cycles of organisms from waterfowl to amphibians to algae being affected. A single plant may produce up to 2.7 million tiny seeds annually. Easily carried by wind and water, the seeds germinate in moist soils after overwintering. The plant can also sprout anew from pieces of root left in the soil or water. Once established, loosestrife stands are difficult and costly to remove by mechanical and chemical means. However, research about how invasive plants are portrayed in media indicate that the threat from loosestrife and other infamous invasive plants is driven more by media attention than science. While the species does have negative impacts on the natural environment the scientific literature supports a much more modest assessment of how bad it is outside its native range and that resources would be better spent on preventing disturbance of wetlands than on the removal of purple loosestrife. Plants marketed under the name "European wand loosestrife" (''L. virgatum'') are the same species despite the different name. In some cases the plants sold are sterile, which is preferable. In North America, purple loosestrife may be distinguished from similar native plants (e.g.,

fireweed ''Chamaenerion angustifolium'' is a perennial herbaceous flowering plant in the willowherb family, Onagraceae. It is known in North America as fireweed and in Britain and Ireland as rosebay willowherb. It is also known by the synonyms ''Chameri ...

''Chamerion angustifolium'', blue vervain ''Verbena hastata'',

Liatris ''Liatris'' (), commonly known as gayfeather and blazing star is a genus of flowering plants in the tribe Eupatorieae within the family Asteraceae native to North America (Canada, United States, Mexico and the Bahamas). Some species are used ...

''Liatris'' spp., and

spiraea ''Spiraea'' , sometimes spelled spirea in common names, and commonly known as meadowsweets or steeplebushes, is a genus of about 80 to 100 species

('' Spiraea douglasii'') by its angular stalks which are square in outline, as well as by its leaves, which are in pairs that alternate at right angle and are not serrated.

Biological control

Purple loosestrife provides a model of successful

biological pest control Biological control or biocontrol is a method of controlling pests, whether pest animals such as insects and mites, weeds, or pathogens affecting animals or plants by using other organisms. It relies on predation, parasitism, herbivory, or ot ...

. Research began in 1985 and today the plant is managed well with a number of insects that feed on it. Five species of

beetle Beetles are insects that form the Taxonomic rank, order Coleoptera (), in the superorder Holometabola. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 40 ...

use purple loosestrife as their natural food source, and they can do significant damage to the plant. The beetles used as biological control agents include two species of

leaf beetle The beetle family Chrysomelidae, commonly known as leaf beetles, includes over 37,000 (and probably at least 50,000) species in more than 2,500 genera, making it one of the largest and most commonly encountered of all beetle families. Numerous s ...

: '' Galerucella calmariensis'' and '' Galerucella pusilla''; and three species of

weevil Weevils are beetles belonging to the superfamily Curculionoidea, known for their elongated snouts. They are usually small – less than in length – and herbivorous. Approximately 97,000 species of weevils are known. They belong to several fa ...

: ''

'', '' Nanophyes breves'', and '' Nanophyes marmoratus''. Infestations of either of the '' Galerucella'' species is extremely effective in wiping out a stand of purple loosestrife, defoliating up to 100% of the plants in an area. The moth ''

'' is

polyphagous Feeding is the process by which organisms, typically animals, obtain food. Terminology often uses either the suffixes -vore, -vory, or -vorous from Latin ''vorare'', meaning "to devour", or -phage, -phagy, or -phagous from Greek φαγε ...

and a pest species itself, and unsuitable for biological control.

References

External links

Invading Species.com
Ontario Ministry of Natural Resources and Ontario Federation of Anglers and Hunters
Species Profile - Purple Loosestrife (''Lythrum salicaria'')
National Invasive Species Information Center,

United States National Agricultural Library The United States National Agricultural Library (NAL) is one of the world's largest agricultural research libraries, and serves as a national library of the United States and as the library of the United States Department of Agriculture. Locate ...

. Lists general information and resources for Purple Loosestrife. {{Taxonbar, from=Q157513 salicaria Flora of Europe Flora of temperate Asia Flora of tropical Asia Flora of North Africa Flora of Queensland Flora of South Australia Flora of Tasmania Flora of Victoria (state) Myrtales of Australia Plants described in 1753 Taxa named by Carl Linnaeus Flora invasive in North America