Critically Imperiled Plant Profile (Not Listed or Proposed under the Endangered Species Act)
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.
This plant, like others in the sunflower family (Asteraceae), has flowers aggregated into heads.
Northern wormwood flowers close-up.
Northern wormwood habitat.
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
More Information
- Washington Natural Heritage Reference Desk: Artemisia campestris ssp. borealis var. wormskjoldii (PDF, 122 KB)
- USFWS species profile
- USFWS Species assessment form for northern wormwood (PDF, 147 KB)
- Oregon Department of Agriculture Plant Conservation Profile
- PLANTS Profile - Artemisia campestris ssp. borealis var. wormskjoldii, northern wormwood