Achillea alpina L.
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Basis for Listing
Achillea alpina was listed as state threatened in 1996 because of concern for the vulnerability of the small populations currently known in Minnesota. The species was discovered in Minnesota in 1939 at a site north of Longworth in Roseau County, near the Canadian border. It was not relocated there, or elsewhere, until 1983 when a Minnesota DNR botanist returned to the original collection site and found a colony of more than 50 plants. The survival of this population was confirmed as recently as 2008. In 1992, an undocumented sighting was reported from a swamp along the Moose River in nearby Marshall County. This site awaits further investigation. Although surveys of remote sites in Roseau, Kittson, and Marshall counties have not resulted in the discovery of any new populations, these counties still have large tracts of nearly inaccessible land that could potentially harbor additional populations.
Achillea alpina is a monoecious, perennial herb 5-8 dm (20-31 in.) tall with white flowers. A terminal inflorescence is comprised of 10-25+ heads, each head with 6-8 ray flowers and 25-30 disk flowers. This species is easily distinguished from other Achillea species by its simple, pinnatifid, incised leaves with narrow, closely set segments. The common A. millefolium (yarrow) has bipinnately dissected leaves, and A. ptarmica (sneezeweed) has simply serrate leaves.
In Minnesota and throughout its range, A. alpina occurs in open woods, shallow swamps, wet areas, and meadows. Minnesota habitats are in the far northwest part of the state and occur in loamy soil in sunny or partially shaded wetland edges.
Biology / Life History
Achillea alpina is a monoecious, perennial that flowers in late summer. It is insect-pollinated, but little more is known about the life history of this species. The population in Roseau County has a history of observation that spans nearly 70 years. This could indicate the species' ability to maintain a long-term presence in suitable habitat.
Conservation / Management
Threats to A. alpina habitat have not been thoroughly analyzed, but likely include land uses practices that would directly degrade the habitat or indirectly change the hydrology of the site. Activities potentially requiring conservation considerations include agricultural practices, livestock grazing, forest management, drainage projects, and herbicide treatments.
Conservation Efforts in Minnesota
The only documented occurrence of A. alpina is in a state-managed wildlife area. However, no specific conservation efforts have yet been undertaken on behalf of this species.
Trock, D. K. 2006. Achillea. Pages 492-494 in Flora of North America Editorial Committee, editors. Flora of North America north of Mexico. Volume 19. Oxford University Press, New York, New York.