Achillea borealis Bong.

Common Yarrow; Thousand Leaf; Milfoil

Herb

Perennial

Vascular

Common Yarrow is a complex of native and introduced plants that have hybridized, forming diploid, tetraploid, pentaploid, hexaploid, septaploid, and octoploid populations. It has variously been treated as several species, as one species with multiple varieties, or as a single highly variable species. It occurs throughout the northern hemisphere. In Alabama, Common Yarrow can be found statewide. It is often cultivated and persists around old home sites. It can also be found on roadsides, in fields and pastures, in vacant lots, and on waste ground. Common Yarrow is a perennial with short rhizomes and sometimes stolons. The stems are erect and branched above the middle. Stems are from 1-3 feet in height. The stems are densely lanate (woolly) pubescent to almost glabrous. Leaves are basal and cauline. The cauline leaves are alternate on the stem. The leaves are petiolate or sessile and 1-2 pinnately lobed. The leaves are densely lanate to almost glabrous. Flowers are produced in heads. The heads are terminal in flat topped corymbs. There are 3-8 white ray flowers per head and 10-20 white disc flowers. The fruit is a winged achene. Common Yarrow is widely cultivated as an ornamental and as an herb. It is readily available from nurseries, and several varieties are available including dwarf forms and forms with pink flowers. Common Yarrow grows well in almost any soil. It can become weedy and aggressive in the flower bed. The genus is named for Achilles, hero of the Trojan War. He is said to have used the plant to treat soldier’s wounds on the battlefield.--A. Diamond

In most earlier floras and treatments this species was referred to as A. millefolium L., however, it may be that this taxon was misapplied (Weakley 2015).

Native FACU (NWPL)

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