YARROW: CHARACTERISTICS, HABITAT, CARE, DISEASES - BIOLOGY - 2025

The yarrow (Achillea millefolium) is a perennial aromatic herb belonging to the Asteraceae family. It is commonly known as yarrow, thousand leaves, hundred in branch, plumage, camphor, plumage and golden royal.

This species can form one or more stems that are usually simple or branched. The root is made up of stolons and rhizomes, which serve to propagate it more easily even than from its seeds.

Yarrow (Achillea millefolium). Source: Achillea millefolium

The feather-like leaves are characteristic of this species and are arranged as alternate, bipinnate, or tripinnate. It develops corymb inflorescences within which are grouped white, pink or purple ligulate flowers, as well as white or yellow disk flowers.

This species is found in grasslands, forests and some disturbed places in high areas and can behave as invasive. Its distribution is circumpolar, that is, it is present throughout the northern hemisphere. It is possibly native to Mexico where there are exotic varieties, although there is no detailed data on this.

It is an aromatic plant, with wide uses in traditional medicine. It is used as a stimulant, analgesic, for the relief of coughs, asthma, hair growth, mouthwash, relief of gastritis, colitis, treatment of gout, bleeding or wounds, ovarian cysts, treatment of hemorrhoids, hepatitis, measles, skin ulcers or sinusitis, among others.

characteristics

Appearance

It is a herbaceous and perennial plant whose root is made up of stolons and rhizomes. The height of this grass can be between 20 cm and 1 m.

It can develop from 1 to 4 erect, simple or branched stems, with a dense tomentum.

Leaves

The leaves are alternate, 20 cm long, can be bipinnate or tripinnate, with linear, oblong or lanceolate morphology. The lower leaves are lanceolate and show a short petiole, while the rest of the leaves are sessile.

flowers

The flowers are grouped in panicle-like inflorescences like a corymb (flowers distributed in a plane). The peduncles are about 5 mm long.

Regarding the floral structures, they have a bell-shaped involvement measuring between 3 and 5 mm long and about 3 mm wide. The bracts are arranged in a series, where the longest are up to 5 mm, do not have pubescence, have a green midrib and brown edges.

Yarrow has corymb-like inflorescences. Source: pixabay.com

The receptacle is conical in shape and the flowers are ligulate and disc. The ligulate flowers have white, light pink or purple corollas, only female; while those of the disk have yellow or white corollas, hermaphrodites, with a tubular shape and are between 2 and 3 mm long.

In the southern hemisphere it blooms from late April to early July, while in the northern hemisphere it blooms from July to mid-September.

The flowers of this aromatic herb have active principles such as tannins, flavonoids, vitamin C, coumarins, essential oils, which make it interesting for treatments based on homeopathy.

Fruit

The fruit of the yarrow corresponds to an achene with an oblong or obovate shape, compressed, devoid of pubescence, measuring 3 mm in length, its color is gray and it shows fine striations. It does not present vilano.

Taxonomy

-Species: Achillea millefolium L.

Some synonyms for this species are: Achillea alpicola, Achillea arenicola, Achillea borealis subsp. arenicola, Achillea borealis subsp. californica, Achillea califórnica, Achillea gigantea, Achillea lanulosa, Achillea lanulosa subsp. alpicola, Achillea megacephala, Achillea millefolium subsp. borealis, Achillea millefolium subsp. occidentalis. Achillea millefolium var. californica or Achillea millefolium var. gigantea, among others.

Habitat and distribution

Yarrow grows in clearings in pine oak forests as a ruderal species, usually on the edges of fields. Sometimes this plant develops as a weed in the highlands.

In this sense, yarrow can behave as an invasive species and displace desirable vegetation if it is not properly managed.

Common yarrow (Achillea millefolium). Source: pixabay.com

In Mexico, this species grows up to 3700 meters above sea level. Especially in this country it is distributed in temperate regions such as Baja California Norte, Chiapas, Coahuila, Chihuahua, Durango, Guanajuato, Guerrero, State of Mexico, Morelos, Nuevo León, Oaxaca, San Luis de Potosí, Sonora, Veracruz or Tamaulipas, among others.

In addition to Mexico, this plant can inhabit the temperate zones of the southern hemisphere.

Applications

This species is well known as a medicinal plant, and it is used both on the European and American continents.

For example, the stalk of yarrow has been used by Native American tribes as a pain reliever. In addition, its infusion, or the vapors of the infusion, has also been used to relieve headaches especially.

The roots of this plant serve as stimulants. To do this, a portion of the root is chewed and the saliva produced from this action can be applied to the area to be treated. Another use is that yarrow tea is indicated to reduce fever and insomnia.

In addition, yarrow is indicated for the relief of coughs, asthma, to grow hair, as a mouthwash, for the relief of gastritis, colitis, treatment of gout, for hemorrhages (nasal, vaginal, of the womb), treatment of hemorrhoids, hepatitis, ovarian cysts, measles, skin ulcers or sinusitis, among others.

Just as yarrow is used as a plant with medicinal powers, it is also used as an ornamental for gardens or public spaces due to the few demands regarding its maintenance.

In the Nordic countries yarrow was used to make beer to replace hops. In Germany it was common to use yarrow in barrels to preserve wine.

Yarrow can behave like an invasive species. Source: pixabay.com

Care

Light

Yarrow requires exposure to the sun, therefore, it is advisable to place it in a place where it receives sufficient direct natural lighting.

Sowing

To propagate this herb the seeds must be placed at a depth of ¼ inch (6.40 mm) because they require light to germinate.

Also, these seeds should be exposed to a temperature of 64 to 75 degrees Fahrenheit (17 to 24 ºC). Sowing is recommended on soil without manure, and in these conditions it normally germinates after 15 days. The optimal time is in early March, and it should be transplanted in early May.

However, reproduction by seeds is not the most used because these are not easily available on the market. For this, it is recommended to collect the seeds directly from the wild specimens in the field.

To extend the longevity of this herb it is recommended to divide the adult plant and replant every two years at a distance of 12 to 18 inches between them (30 to 45 cm).

Floor

Regarding the substrate, this species particularly develops better in relatively degraded or poorly developed soils, but it must have good drainage.

It grows well in dry, sandy, humid, clay soils with high salt content.

Irrigation

This species is tolerant to drought, therefore, irrigation should only be necessary according to environmental conditions. For example, if you are in a high temperature zone, water at field capacity once a week, and if you are in a temperate zone, watering should be once every 15 days.

Pruning

Yarrow is often pruned to remove mostly faded-looking flowers to stimulate the flowering process.

Diseases

Yarrow is often susceptible to attack by mold or root rot when planted in poorly drained soil.

Pests

This herb can act as a host for aphids. These insects devour the flowers and leaves of the yarrow.

This pest usually appears in cases where excessive watering is applied to the plant. Its elimination is easy, since once its presence is detected in the crop, potassium soap or garlic extract must be applied.

References

1. Muñoz, L., Santos, MT, Alonso, T. 1999. Spanish medicinal plants. Achillea millefolium L. (Asteraceae). (Yarrow). Salamanca University Editions. Stud. Bot. 18: 117-129.
2. Conabio. 2019. Achillea millefolium L. Taken from: conabio.gob.mx
3. Plant Guide. 2001. Common Yarrow Achillea millefolium. Taken from: plants.usda.gov
4. Flora of North America. 2019. Achillea millefolium Linnaeus. Taken from: efloras.org
5. Catalog of Life: 2019 Annual Checklist. Species details: Achillea millefolium L. Taken from: catalogueoflife.org
6. Tropics. 2019. Achillea millefolium L. Taken from: tropicos.org
7. Cruz Hernández, VM, Álvarez, S. 2004. Naturist dictionary of health. Books online. Pages 272-273. Mexico. Taken from: books.google.co.ve
8. The tree. 2019. Yarrow. Taken from: elarbol.org