Lythrum salicaria | |
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Scientific classification | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Eudicots |
Clade: | Rosids |
Order: | Myrtales |
Family: | Lythraceae |
Genus: | Lythrum |
Species: | L. salicaria |
Binomial name | |
Lythrum salicaria | |
Lythrum salicaria or purple loosestrife [2] is a flowering plant belonging to the family Lythraceae. It should not be confused with other plants sharing the name loosestrife that are members of the family Primulaceae. Other names include spiked loosestrife and purple Lythrum. This herbaceous perennial is native to Europe and Asia, [3] and possibly Australia. [4]
The generic name Lythrum is derived from the Greek 'lythron', meaning blood, in reference to the flower colour in some species. [5] However, Pliny (A.D. 23–79) stated that Lythrum is named for Lysimachus, an army general and friend of Alexander the Great. Lysimachus is derived from the Greek lysis, meaning "loosing" and mache, meaning "strife". [6]
The specific epithet salicaria derives from the similarity of the leaves to those of willows or Salix species. [6]
The English word 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: "[The plant] may in englishe be called red loosestryfe or purple loosestryfe." [6]
Purple loosestrife was referred to several times as 'long purples' by John Clare, such as in his 1821 poem The Wildflower Nosegay: [7]
"Where on the water op'd the lily buds
And fine long purples shadow'd in the lake..."
— Volume II of The Village Minstrel and Other Poems, John Clare, pg. 133
Lythrum salicaria can grow 1–2 m (3 ft 3 in – 6 ft 7 in) tall, forming clonal colonies 1.5 m (4 ft 11 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, 3–10 centimetres (1–4 in) long and 5–15 millimetres (3⁄16–9⁄16 in) broad, downy and sessile, and arranged opposite or in whorls of three.
The flowers are reddish purple, 10–20 millimetres (1⁄2–3⁄4 in) in diameter, with six petals (occasionally five) and 12 stamens, and are clustered tightly in the axils of bracts or leaves; 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. [2] [8] [9] The flowers are visited by many types of insects, and can be characterized by a generalized pollination syndrome. [10]
The fruit is a small 3–4 millimetres (1⁄8–5⁄32 in) capsule [11] containing numerous minute seeds. 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. [2] [8] [9]
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 intermediumLedeb. ex Colla is also now considered synonymous. [2] [9] [12]
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. [8] [12] [13] [14] [15] 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; [16] the question is considered unresolved by Australian authorities. [4]
Found in ditches, wet meadows and marshes and along sides of lakes. [17] In North America, purple loosestrife can invade sedge meadows. [18]
The flowers are pollinated by long-tongued insects, including bees and butterflies. [9]
A number of insects 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 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.
Caterpillars of the engrailed moth ( Ectropis crepuscularia ), a polyphagous geometer moth, also feed on purple loosestrife.
It has been used as an astringent medicinal herb to treat diarrhea and dysentery; it is considered safe to use for all ages, including babies. [19] It is also cultivated as an ornamental plant 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 cultivars have been selected for variation in flower colour, including:
The cultivars ‘Blush’ [21] with blush-pink flowers, and 'Feuerkerze' [22] with rose-red flowers have gained the Royal Horticultural Society's Award of Garden Merit. [23]
It has also been introduced in many areas of North America by bee keepers,[ citation needed ] due to its abundance of flowers which provide an important source of nectar. [24]
Purple loosestrife has been introduced into temperate New Zealand and North America where it is now widely naturalised (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. [25]
A single plant may produce up to 2.7 million tiny seeds annually. [26] 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.
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 Chamerion angustifolium, blue vervain Verbena hastata, Liatris Liatris spp., and spiraea ( 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.
Purple loosestrife provides a model of successful biological pest control. Research began in 1985 and today the plant is managed well with a number of insects that feed on it. Five species of beetle 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: Galerucella calmariensis and Galerucella pusilla ; and three species of weevil: Hylobius transversovittatus , 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 Ectropis crepuscularia is polyphagous and a pest species itself, and unsuitable for biological control. [27]
Centaurea is a genus of over 700 species of herbaceous thistle-like flowering plants in the family Asteraceae. Members of the genus are found only north of the equator, mostly in the Eastern Hemisphere; the Middle East and surrounding regions are particularly species-rich.
The raspberry is the edible fruit of a multitude of plant species in the genus Rubus of the rose family, most of which are in the subgenus Idaeobatus. The name also applies to these plants themselves. Raspberries are perennial with woody stems.
Lythraceae is a family of flowering plants, including 32 genera, with about 620 species of herbs, shrubs, and trees. The larger genera include Cuphea, Lagerstroemia (56), Nesaea (50), Rotala (45), and Lythrum (35). It also includes the members of the former families of the pomegranate and of the water caltrop. Lythraceae has a worldwide distribution, with most species in the tropics, but ranging into temperate climate regions as well.
The insects of the beetle family Chrysomelidae are commonly known as leaf beetles, and include over 37,000 species in more than 2,500 genera, making up one of the largest and most commonly encountered of all beetle families. Numerous subfamilies are recognized, but the precise taxonomy and systematics are likely to change with ongoing research.
Lysimachia is a genus consisting of 193 accepted species of flowering plants traditionally classified in the family Primulaceae. Based on a molecular phylogenetic study it was transferred to the family Myrsinaceae, before this family was later merged into the Primulaceae.
Anemonoides nemorosa, the wood anemone, is an early-spring flowering plant in the buttercup family Ranunculaceae, native to Europe. Other common names include windflower, European thimbleweed, and smell fox, an allusion to the musky smell of the leaves. It is a perennial herbaceous plant growing 5–15 cm (2–6 in) tall.
Commonly known as hellebores, the Eurasian genus Helleborus consists of approximately 20 species of herbaceous or evergreen perennial flowering plants in the family Ranunculaceae, within which it gave its name to the tribe of Helleboreae. Many hellebore species are poisonous.
Caltha palustris, known as marsh-marigold and kingcup, is a small to medium sized perennial herbaceous plant of the buttercup family, native to marshes, fens, ditches and wet woodland in temperate regions of the Northern Hemisphere. It flowers between April and August, dependent on altitude and latitude, but occasional flowers may occur at other times.
Lythrum is a genus of 38 species of flowering plants native to the temperate world. Commonly known as loosestrife, they are among 32 genera of the family Lythraceae.
Cirsium arvense is a perennial species of flowering plant in the family Asteraceae, native throughout Europe and western Asia, northern Africa and widely introduced elsewhere. The standard English name in its native area is creeping thistle. It is also commonly known as Canada thistle and field thistle.
Chamaerops is a genus of flowering plants in the family Arecaceae. It contains only one species, Chamaerops humilis, variously called European fan palm or the Mediterranean dwarf palm. It is one of the most cold-hardy palms and is used in landscaping in temperate climates.
Pittosporum tenuifolium is a small evergreen tree endemic to New Zealand – up to 10 m (33 ft) – commonly known as kōhūhū and black matipo, and by other Māori names kohukohu and tawhiwhi. Its small, very dark, reddish-purple flowers generally go unnoticed, and are scented only at night. The Latin tenuifolium means "slender-leaved"
Asclepias purpurascens, the purple milkweed, is a herbaceous plant species. It is in the genus Asclepias, making it a type of milkweed. It is native to the Eastern, Southern and Midwestern United States similar to the range of the common milkweed. The plant gets its name from the flowers that first develop a pink color but then turn darker purple as they mature. Unlike common milkweed, purple milkweed prefers some shade and is considered a plant of partial shade. It is also considered an indicator of oak savanna, especially in Wisconsin. The species rarely produces seed pods which are smooth, instead of the rough warty ones produced by common milkweed.
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. This plant is regarded as an invasive species in North America and the weevil has been introduced into both the United States and Canada in an effort to control the plant.
Galerucella calmariensis, sometimes Neogalerucella calmariensis, is a species of leaf beetle in the family Chrysomelidae. It is commonly known as the black-margined loosestrife beetle and is native to Europe and Northern Asia where both adults and larvae feed on purple loosestrife. It has been introduced in North America as a biological control agent for purple loosestrife.
Spiranthes diluvialis is a rare species of orchid known as Ute lady's tresses. The species name diluvialis means "of the flood". It is native to the western United States, where there are scattered, mostly small occurrences in the states of Colorado, Idaho, Montana, Nebraska, Nevada, Utah, Washington, and Wyoming. An occurrence was recently discovered in southern British Columbia. The plant faces a number of threats to its existence. It is a federally listed threatened species of the United States.
Sesbania punicea is an ornamental shrub with reddish-orange flowers. It has deciduous leaves and grows to a height of 15 feet. This plant has a high demand for water, and thrives in swamps or wet areas. It requires a mildly acidic soil, with a pH between 6.1 and 6.5.
Galerucella is a genus of leaf beetles in the family Chrysomelidae described by George Robert Crotch in 1873. It is widely distributed but absent in the Neotropics. Some species feed on waterlilies and are used as biocontrol of introduced, invasive waterlilies. Galerucella tenella feed on strawberry plants.
Apion apricans is a species of seed weevils native to Europe. It is widespread everywhere. Damages clover and wild. The beetle is 3–3.5 mm in size, black, with a metallic hue, the body is pear-shaped, the legs are partially yellow; rostrum long, almost straight; apex of antennae black, base - red. Egg - 0.3-0.5 mm, yellowish, long, smooth. Larva 2–2.5 mm, white with a creamy hue, curved, dark brown head, on the upper jaws on each side of three growths, the middle of them increased; instead of legs six pairs of small knolls. Pupa 3–3.5 mm, yellowish white.
Lythrum virgatum, the wand loosestrife, is a species of flowering plant in the family Lythraceae, native to wet areas of the Eurasian steppes, and introduced to France, Germany, and the United States. The unimproved species and a number of cultivars are available from commercial suppliers. It is considered an invasive species in some jurisdictions.