Achillea millefolium, known commonly as yarrow /ˈjæroʊ/ or common yarrow, is a flowering plant in the family Asteraceae. It is native to temperate regions of the Northern Hemisphere in Asia, Europe, and North America. In New Mexico and southern Colorado, it is called plumajillo (Spanish for 'little feather') from its leaf shape and texture. In antiquity, yarrow was known as herbal militaris, for its use in stanching the flow of blood from wounds. Other common names...
Regularity: Regularly occurring
Currently: Present
Confidence: Confident
Regularity: Regularly occurring
Currently: Present
Confidence: Confident
Perennials, 6–65+ cm (usually rhizomatous, sometimes stoloniferous). Stems 1(–4), erect, simple or branched, densely lanate-tomentose to glabrate. Leaves petiolate (proximally) or sessile (distally, weakly clasping and gradually reduced); blades oblong or lanceolate, 3.5–35+ cm × 5–35 mm, 1–2-pinnately lobed (ultimate lobes ± lanceolate, often arrayed in multiple planes), faces glabrate to sparsely tomentose or densely lanate. Heads 10–100+, in simple or compound, corymbiform arrays. Phyllaries 20–30 in ± 3 series, (light green, midribs dark green to yellowish, margins green to light or dark brown) ovate to lanceolate, abaxial faces tomentose. Receptacles convex; paleae lanceolate, 1.5–4 mm. Ray florets (3–)5–8, pistillate, fertile; corollas white or light pink to deep purple, laminae 1.5–3 × 1.5–3 mm. Disc florets 10–20; corollas white to grayish white, 2–4.5 mm. Cypselae 1–2 mm (margins broadly winged). 2n = 18, 27, 36, 45, 54, 63, 72 (including counts from Europe).
"Erect herb. Leaves alternate, linear to lanceolate, 2-3-pinnatifid, to 12 x 2.5 cm at the base. Corymbs terminal, to 10 cm wide. Capitula numerous, radiate; peduncle 4 mm. Involucre oblong. Phyllaries several-seriate, lanceolate. Receptacle convex. Outer ray florets pistillate, c. 6, rose; ligule 3-toothed. Inner disk florets bisexual. Achenes compressed. Pappus 0."
Yarrow is a common plant that has naturalized in all counties of Illinois (see Distribution Map). The variety of Yarrow that occurs in Illinois is probably native to Eurasia, although there is a variety of this plant that is native to western North America. This latter variety tends to be smaller in size and its foliage is more heavily covered with woolly hairs. Habitats include mesic to dry prairies, pastures, fallow fields, grassy waste areas, and edges of paths, yards, or hedges. Disturbed areas are preferred; Yarrow persists in native habitats (e.g., prairies) to a limited extent. Yarrow is often cultivated in flower and herbal gardens, from which it occasionally escapes. Faunal Associations
More info for the term: forb
Forb
This species is not threatened.
Comments: This taxon is recognized (as a tetraploid) by M.A. Nobs in Ferris (1960) and by Kartesz (1999); Munz (1974) for southern California followed Nobs' treatment (but not covering this taxon). It is not mentioned by Jepson (1925), or by Howell (1970) for Marin County. This taxon is considered a synonym of the species by D.J. Keil in Hickman (1993), who also states that the species is a "highly variable polyploid complex", and by Munz (1959). Cronquist (1994) discussed the variability in this species (with a focus on the Intermountain region), more or less recognizing several infrataxa in his discussion (although not providing a key).
The inflorescence has 4 to 9 phyllaries and contains ray and disk flowers which are white to pink. The generally 3 to 8 ray flowers are ovate to round. Disk flowers range from 15 to 40. The inflorescence is produced in a flat-topped cluster. The fruits are small achenes.[3]
The plant has a strong, sweet scent, similar to chrysanthemums.[1]
Yarrow grows from sea level to 3,500 metres (11,500 ft) in elevation. The plant commonly flowers from May through June. Common yarrow is frequently found in the mildly disturbed soil of grasslands and open forests. Active growth occurs in the spring.[1][3]
In North America, both native and introduced genotypes, and both diploid and polyploid plants are found.[4] It is found in every habitat throughout California except the Colorado and Mojave Deserts.[5][6] common yarrow produces an average yield of 43,000 plants per acre, with a total dry weight of 10,500 lbs.[7]
The several varieties and subspecies include:
For propagation, seeds require light for germination, so optimal germination occurs when planted no deeper than one-quarter inch (6 mm). Seeds also require a germination temperature of 18-24° (64-75 °F). It has a relatively short life in some situations, but may be prolonged by division in the spring every other year, and planting 12–18 in (30–46 cm) apart. It can become invasive.[18]
The species use in traditional gardens has generally been superseded by cultivars with specific 'improved' qualities.[19] Some are used as drought tolerant lawn replacements, with periodic mowing.[20] The many different ornamental cultivars include: 'Paprika',[21] 'Cerise Queen', 'Red Beauty',[22] 'Red Velvet',[23] 'Saucy Seduction', 'Strawberry Seduction' (red), 'Island Pink' (pink),[24] and 'Calistoga' (white),[25] and 'Sonoma Coast' (white).[26] Several, including 'Kelwayi',[27] and 'Lansdorferglut' (both pink)[28] have gained the Royal Horticultural Society's Award of Garden Merit. The many hybrids of this species designated Achillea x taygetea are useful garden subjects,[29] including: 'Appleblossom', 'Fanal', 'Hoffnung', and 'Moonshine'.[30]
Yarrow, Achillea millefolium, is considered an especially useful companion plant, repelling some insect pests while attracting good, predatory ones. It attracts predatory wasps, which drink the nectar and then use insect pests as food for their larvae. Similarly, it attracts ladybirds and hoverflies.[17]
The herb is purported to be a diaphoretic, astringent,[31]tonic,[31]stimulant and mild aromatic. It contains isovaleric acid, salicylic acid, asparagin, sterols, flavonoids, bitters, tannins, and coumarins. The plant also has a long history as a powerful 'healing herb' used topically for wounds, cuts and abrasions. The genus name Achillea is derived from mythical Greek character, Achilles,[31] who reportedly carried it with his army to treat battle wounds. This medicinal action is also reflected in some of the common names mentioned below, such as staunchweed and soldier's woundwort.[1]
The stalks are dried and used as a randomising agent in I Ching divination.[32]
In the Middle Ages, yarrow was part of a herbal mixture known as gruit used in the flavouring of beer prior to the use of hops.[citation needed] The flowers and leaves are used in making some liquors and bitters.[1]
Traditional names for A. millefolium include arrowroot, bad man's plaything, bloodwort, carpenter's weed, death flower, devil's nettle, eerie, field hops, gearwe, hundred leaved grass, knight's milefoil, knyghten, milefolium, milfoil, millefoil, noble yarrow, nosebleed, old man's mustard, old man's pepper, sanguinary, seven year's love, snake's grass, soldier, soldier's woundwort, stanchweed, thousand seal, woundwort, yarroway, yerw. The English name yarrow comes from the Saxon (Old English) word gearwe, which is related to both the Dutch word gerw and the Old High German word garawa.[33]
Yarrow has also been used as a food, and was very popular as a vegetable in the 17th century. The younger leaves are said to be a pleasant leaf vegetable when cooked like spinach, or in a soup. Yarrow is sweet with a slight bitter taste. The leaves can also be dried and used as a herb in cooking.
A. millefolium has seen historical use as a medicine, often because of its astringent effects.[1]
The dark blue essential oil, extracted by steam distillation of the flowers, is generally used as an anti-inflammatory[34] or in chest rubs for colds and influenza.[35]
The leaves encourage clotting, so it can be used fresh for nosebleeds.[36] The aerial parts of the plant are used for phlegm conditions, as a bitter digestive tonic to encourage bile flow, and as a diuretic.[37] The aerial parts act as a tonic for the blood, stimulate the circulation, and can be used for high blood pressure; it is also useful in menstrual disorders, and as an effective sweating remedy to bring down fevers.[1]
Yarrow intensifies the medicinal action of other herbs taken with it.[38] It is reported[39] to be associated with the treatment of the following ailments:
Pain,[40] antiphlogistic,[41][42]bleeding, gastrointestinal disorders,[41] choleretic[43] inflammation,[44] emmenagogue,[45] stomachache.[46]
Chinese proverbs claim yarrow brightens the eyes and promotes intelligence. Yarrow and tortoiseshell are considered to be lucky in Chinese tradition.[47]
In classical Greece, Homer tells of the centaur Chiron, who conveyed herbal secrets to his human pupils, and taught Achilles to use yarrow on the battle grounds of Troy.[48]
Yarrow, Achillea millefolium and its North American varieties, was used in traditional Native American herbal medicine by tribes across the continent.[49] The Navajo considered it to be a "life medicine", chewed it for toothaches, and poured an infusion into ears for earaches. The Miwok in California used the plant as an analgesic and head cold remedy.[49]
Several tribes of the Plains Indians used common yarrow. The Pawnee used the stalk for pain relief. The Chippewa used the leaves for headaches by inhaling it in a steam. They also chewed the roots and applied the saliva to their appendages as a stimulant. The Cherokee drank a tea of common yarrow to reduce fever and aid in restful sleep.[49]
Among the Zuni people use the occidentalis variety medicinally. The blossoms and root are chewed, and the juice applied before fire-walking or fire-eating. A poultice of the pulverized plant is mixed with water and applied to burns.[50] Recently it was reported that treatment with Achillea millefolium may attenuate disease severity, inflammatory responses, and demyelinating lesions in a mouse model of Multiple Sclerosis.[51]
In rare cases, yarrow can cause severe allergic skin rashes; prolonged use can increase the skin's photosensitivity.[52] This can be triggered initially when wet skin comes into contact with cut grass and yarrow together.
In one study, aqueous extracts of yarrow impaired the sperm production of laboratory rats.[53]
Several cavity-nesting birds, including the common starling, use yarrow to line their nests. Experiments conducted on the tree swallow, which does not use yarrow, suggest that adding yarrow to nests inhibits the growth of parasites.[54]
Its essential oil kills the larvae of the mosquito Aedes albopictus.[55]
Other Achillea species have similar foliage and flowers, including: Achillea ageratifolia and Achillea nobilis.
Other plants with white flowers in large compound umbels may be confused with Achillea millefolium, these include: water parsnip—Sium suave (swamp parsnip); western water hemlock—Cicuta douglasii (poison hemlock); and spotted water hemlock—Cicuta maculata (spotted parsley, spotted cowbane). Water parsnip and water hemlock have clusters of small white flowers that are shaped like umbrellas, and both grow in moist soils. Water parsnip leaves are once compound, and water hemlock leaves are three times compound. Water hemlock has a large swelling at the stem base. All parts of water hemlock are highly poisonous.[56]
Field of Yarrow in Russia.