Achillea millefolium L.

by Judi Buckley, Native Plants Class
Common Names: Yarrow, thousand leaf, old man's pepper, knight's milfoil, soldier's woundwort.
Family: Asteraceae
Synonymy:
Etymology: Achillea refers to the Greek hero, Achilles, who used this plant to heal his soldier's wounds. The species name, millefolium, means "thousand leaves" in reference to the many fine dissections of the leaf (4).

Identification
Growth Form: Rhizomatous, perennial forb, often growing in small clumps.
Roots: Vigorous, horizontal rootstalks (3).
Stems : Stems erect, 30 -80 cm tall, branching toward the top. Grayish-green appearance caused by white, silky, oppressed hairs.
Leaves: Aromatic, finely dissected, bi-pinnate leaves with fern-like appearance (1). Narrowly oblong to lanceolate in outline, alternate. Sparsely woolly atop while glandular underneath (5). Those of basal offshoots and lower portion of the stem usually largest and longest petioled. Leaves reduced and sessile upward on the stem.
Inflorescence/Flower: Small white, cream colored or sometimes pinkish flower heads arranged in rounded to flat topped terminal clusters.
Fruit: Fruits are small achenes. Regenerates from rhizomes and from colonization through short distance wind dispersal of seeds.
Similar Species:

Ecology
Life History: Perennial
Native/ Introduced: Native to Eurasia but widely naturalized in the U.S. (3).
Photosynthetic pathway:
Phenology: Flowers from June - August. Fruiting from August - September.
Distribution/habitat: Circumboreal in North America. Grows from Alaska, across Canada, throughout the U.S. and into northern Mexico. Common Yarrow occurs on grasslands and shrubby plains to subalpine zones (3, 5).

Uses
Wildlife: Cattle graze it moderately, while sheep and pronghorn select flower heads. Deer, rabbits, small rodents and grouse use its foliage (3).
Ethnobotanical: Used medicinally by at least 58 different Indian tribes to stop bleeding of wounds, to treat sores, to alleviate colds and as a mild laxative (2). The Lakota Sioux name for yarrow translates into "Wound Medicine". Cheyenne call it "cough medicine" (2).

References
1. Christopher, John R. 1996. School of Natural Healing. Christopher Publications, Springville, Utah, USA.

2. Gilmore, Melvin R. 1991. Uses of Plants by the Indians of the Missouri River Regions. University of Nebraska Press, Lincoln, Nebraska, USA.

3. Johnson, James R., and Gary E. Larson. 1999. Grassland Plants of the Northern Great Plains. South Dakota State University, Brookings, South Dakota, USA.

4. Kindscher, Kelly. 1992. Medicinal Wild Plants of the Prairie. University Press of Kansas, Lawrence, Kansas, USA.

5. Larsen, Gary E., and James Johnson. Plants of the Black Hills and ear Lodge Mountains. South Dakota State University, Brookings, South Dakota, USA.