Critically Imperiled Plant Profile
(Not Listed or Proposed under the Endangered Species Act)

Northern wormwood.
Northern wormwood, a perennial relative of sagebrush, is restricted to exposed basalt, cobbly-sandy terraces, and sand habitat along the banks of the Columbia River. Its current distribution - two populations 200 miles apart - are what remain after historical construction of several dams on the Columbia River, and subsequent flooding of its habitat.

Northern wormwood flowers.
This plant, like others in the sunflower family (Asteraceae), has flowers aggregated into heads.

Northern wormwood flowers close-up.
Northern wormwood flowers close-up.

cliff milkvetch habitat.
Northern wormwood habitat.

Artemisia campestris ssp. borealis var. wormskjoldii range map.
Artemisia campestris ssp. borealis var. wormskjoldii range map.

Artemisia campestris ssp. borealis var. wormskjoldii, northern wormwood

Threats

  • This plant is currently known from only two sites, both along banks of Columbia River reservoirs
  • Alteration of water regimes is a major threat
  • Invasive exotic plants, particularly diffuse knapweed (Centaurea diffusa)
  • Recreational use of its sites, including trampling and off-road vehicles
  • Its small, isolated populations make this plant vulnerable to stochastic impacts
  • Other possible threats include horticultural collecting, cattle grazing, and hybridization with other Artemisias

Conservation Status

National Forest and Grassland Occurrence

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