Columbian Whitetop Aster / Center For Plant Conservation
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Plant Profile

Columbian Whitetop Aster (Sericocarpus rigidus)

  • Global Rank: G3 - Vulnerable
  • Legal Status: N/A
  • Family: Asteraceae
  • State: BC, OR, WA
  • Nature Serve ID: 134849
  • Lifeform: Forb/herb
  • Date Inducted in National Collection: 09/01/2001

This perennial herb from the Sunflower family (Asteraceae) is distinguished by tightly clustered flower heads on the shoot ends. They are usually in colonies of 50-200+ shoots that spread vegetatively by rhizomes (an underground, horizontal stem). The shoots that are not flowering are usually less than half the length of the flowering shoots. The leaves can be as long as one inch, are alternate and are placed evenly along the stem. (Pojar &MacKinnon, NHP field Guide, Hitchcock). White top aster habitat is open grassland and is dominated by Idaho fescue (Festuca idahoensis). Fire is thought to have played a major historical role in the maintenance of the grassland habitats occupied by A. curtus. (NHP Field Guide). Major threats to the species are loss of habitat by Scots broom (Cytisus scoparius), an invasive plant, and by encroaching Douglas fir (Pseudotsuga menziesii) because of the loss of fire. (Hitchcock, et al 1973 ; Giblin 1997; NatureServe 2003; Selected Rare Vascular Plants of Washington 2000; USDA, NRCS. 2002)

Where is Columbian Whitetop Aster (Sericocarpus rigidus) located in the wild?


Open grasslands dominated by Idaho fescue (Festuca idahoensis) are home to the white-topped aster. And these grasslands are surrounded by Douglas fir trees (Pseudotsuga menziesii). The grasslands are typically moist most of the year, but dry, or moisture-stressed, during late summer. Southern populations occur in clayey soil, central populations in glacial outwash soil and northern populations in exposed bedrock. Other native species found in the grassland home of white-topped aster are snowberry (Symphoricarpos albus), service berry (Almelanchier alnifolia), Oregon sunshine (Eriophyllum lanatum) and early blue violet (Viola adunca). A non-native species found within white-topped asters habitat is Scots broom (Cytisus scoparius). This species poses a threat to Aster curtus by growing in dense stands and altering the soil nutrients. (Rare Care)


Aster curtus is restricted in distribution to only a few regions within the west coast of North America: the Willamette Valley-Puget Lowlands in Oregon and Washington and the southeastern portions of

States & Provinces:

Columbian Whitetop Aster can be found in British Columbia, Oregon, Washington

Which CPC Partners conserve Columbian Whitetop Aster (Sericocarpus rigidus)?

CPC's Plant Sponsorship Program provides long term stewardship of rare plants in our National Collection. We are so grateful for all our donors who have made the Plant Sponsorship Program so successful. We are in the process of acknowledging all our wonderful plant sponsorship donors on our website. This is a work in progress and will be updated regularly.

Conservation Actions

Nature Serve Biotics
  • 05/02/2017

Approximately 80 total element occurrences. However, the number of discrete, isolated populations is somewhat less, and the degree to which many of the occurrences are threatened is significant. Threats include invasion of its habitat by native conifers and non-native shrubs and grasses, as well as development, grazing, and military training exercises.

  • 01/01/2010

Habitat loss: Loss of habitat by invasion of the noxious weed Scots broom (Cytisus scoparius). Fire suppression: The loss of fire allows Douglas fir (Pseduotsuga menziesii) to encroach onto the grasslands (NHP 2000, Giblin 1997). Possibly military trai

  • 01/01/2010

Of the more than 80 sites, many are small, fragmented and isolated. (NHP 2000, Giblin 1997).

  • 01/01/2010

""A Demographic Analysis of the Impact of Army Disturbance on Aster curtus Population Viability""; lead researchers are University of Washington, The Nature Conservancy, and Range Control LCTA On going. Ewing, K. 2002. Mounding as a technique for restoration of prairie on a capped landfill in the Puget Sound lowlands. Restoration Ecology 10:289-296. Kareiva, Peter. 1997. Designing a research plan for an endangered plant on Ft. Lewis Giblin, David Emmett. 1997.The relationships of reproductive biology and disturbance to the rarity of Aster curtus (Cronq.), a Pacific Northwest endemic Clampitt, Christopher Alan. 1984. The ecological life history of Aster curtus, a grassland endemic in a forested region

  • 01/01/2010

The Washington sate Department of Natural Resources Natural Heritage Program holds responsibility for managing the species. Mechanical removal of the invasive Scots Broom (Cytisus scoparius) and prescribed fire to prevent the encroachment of Douglas fir (Pseudotsuga menziesii) are two management tools the agency recommends for controlling threats to white-topped aster.

  • 01/01/2010

In addition to research on Scots broom control and prescribed burns, the Washington Natural Heritage Program and the U.S.D.I. Bureau of Land Management are calling for additional inventories throughout the species range.

  • 01/01/2010

A. curtus seeds were banked in the Miller Seed Vault at the Center for Urban Horticulture; Seattle, WA in the summer of 2003. Additional ex situ resources are needed to ensure conservation of the species.


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Taxon Sericocarpus rigidus
Authority Lindl.
Family Asteraceae
CPC Number 335
ITIS 508083
Duration Perennial
Common Names Columbia white top aster | Curtus' aster | white-top aster
Associated Scientific Names Sericocarpus rigidus | Aster curtus
Distribution Aster curtus is restricted in distribution to only a few regions within the west coast of North America: the Willamette Valley-Puget Lowlands in Oregon and Washington and the southeastern portions of
State Rank
State State Rank
British Columbia S2
Oregon S2
Washington S3
Ecological Relationships

Common Name Name in Text Association Type Source InteractionID
Bees Confirmed Pollinator Link
Wasps Confirmed Pollinator Link
Lead Institution State Reintroduction Type Year of First Outplanting
Institute for Applied Ecology - Oregon Oregon Reintroduction 1999
Institute for Applied Ecology - Oregon Oregon Reintroduction 2000

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