“The Achillea genus was named by Linnaeus in 1753 when he also named this species "Achillea millefolium" from specimens collected in Europe. Thomas Nuttall named this species "Achillea lanulosa" in 1834 from specimens collected by Meriwether Lewis in Idaho in about 1806. Weber states that A. lanulosa and A. millefolium are "very closely related" but different species. Most other botanists, including John Kartesz, ultimate authority for plant names on this web site, treat the two as one species under the name of A. millefolium with A. lanulosa as a synonym.”
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