SafePlants

Yarrow (Achillea millefolium)

Achillea millefolium, commonly known as yarrow or common yarrow, is a well-known plant with a wide distribution. Several varieties and subspecies exist, including the native American species formerly known as Achillea lanulosa, sometimes called Woolly or Western Yarrow.

Considerations for Pets

• Western yarrow contains volatile oils, alkaloids, and glycosides.
• The leaves are finely dissected.

Considerations for Children

• The leaves are finely dissected.

Taxonomy and Nomenclature

• Scientific Name: Achillea millefolium L.
• Common Names: Yarrow, Common Yarrow, Western Yarrow, Milfoil, Boreal Yarrow, California Yarrow, Giant Yarrow, Coast Yarrow, Pacific Yarrow.
• Family: Asteraceae (also known as Compositae or Sunflower family)
• Synonyms: Formerly known as Achillea lanulosa.
• Taxonomic Rank: Subspecies and varieties exist, such as Achillea millefolium subsp. millefolium var., and Achillea millefolium var. alpicola. Also Achillea millefolium L. var. occidentalis DC.

Distribution and Habitat

• Common yarrow is an introduced variety from Eurasia but is widely naturalized in America.
• Western Yarrow is one of the most common wildflowers in the western and prairie regions of the United States.
• Found throughout California (and western U.S.) from the coast.
• Grows "just about anywhere" including by the wayside, in meadows, pastures, and waste grounds.
• Native yarrow is one of the most common prairie plants and can be found in both wet and dry prairies.

Ecological Role

• An aggressive species used for erosion control and habitat restoration.
• Yarrow is a food source for bighorn sheep and pronghorn. Western yarrow can constitute a significant percentage of their summer diet.
• Yarrow provides poor to fair cattle forage and fair to good sheep forage.
• Planting Western Yarrow seeds around construction sites or disturbed soil will attract beneficial insects.

Morphological Characteristics

• Yarrow grows to 3 feet tall and has no branches except near the top.
• Stems: Erect, solitary or loosely clustered, few-branched, woolly-hairy.
• Leaves: Alternate, fern-like, stalked below to sessile above, lanceolate in outline but finely dissected. Leaves equally distributed along the stem.
• Aromatic perennial.
• Forms a spreading carpet of soft, fern-like leaves.
• Drought-tolerant.
• Rhizomatous perennial 1-2 ft tall with erect wooly-villous stems.
• Small, flat flowers in clusters.

Quirky Facts

• Yarrow is one of the least difficult perennial flowers to grow and naturally grows in clusters.

Further Information

• National Plant Data Center (<http://npdc.usda.gov>)
• Great Basin Seed (regarding White Yarrow/Western Yarrow)
• Smithsonian American Art Museum collection (Mary Vaux Walcott illustration of Achillea lanulosa)