Species Profile

Western Silvery Aster

Scientific Name: Symphyotrichum sericeum
Other/Previous Names: Western Silver-leaved Aster,Virgulus sericeus
Taxonomy Group: Vascular Plants
Range: Manitoba, Ontario
Last COSEWIC Assessment: May 2000
Last COSEWIC Designation: Threatened
SARA Status: Schedule 1, Threatened

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Quick Links: | Photo | Description | Distribution and Population | Habitat | Biology | Threats | Protection | Recovery Initiatives | Recovery Team | National Recovery Program | Documents

Image of Western Silvery Aster

Western Silvery Aster Photo 1



The Western Silvery Aster is a perennial with several stems which measure 30 to 70 cm in height. The leaves are densely covered with silvery hairs. The flowers are violet to pink and occur in composite heads at the ends of branches.


Distribution and Population

The Western Silvery Aster occurs in central North America from Manitoba to Texas. In Canada, it is at the northern limit of its distribution and a total of about 6,500 stems occur at two major sites and a number of smaller ones in Ontario and southeastern Manitoba.



Western Silvery Asters are found in well-drained calcareous (alkaline) soils in dry prairies and fields, glacial sand and gravel deposits, dry banks and open oak savannas.



The Western Silvery Aster flowers from early August to mid September. It is pollinated by a variety of insects, but bees are considered the main pollinators. The fruit develops about 3 to 4 weeks after pollination. This aster reproduces mainly through seeds, but can also spread through horizontal rhizomes just below the surface of the soil. Although seed production is naturally low, it decreases in dry years. In addition, about 30% of seed heads can be parasitized by a weevil (beetle), further reducing seed production.



The natural limiting factors for the Western Silvery Aster are not well known, but restricted distribution and low seed production are cause for concern. Loss of habitat as a result of human activities (residential development, recreational use, gravel extraction, fire suppression, pasture enhancement and haying) and invasion of grasslands by alien species and woody vegetation are considered to be limiting factors. Many small populations occurring along roadsides are at risk from road maintenance operations.



Federal Protection

The Western Silvery Aster is protected under the federal Species at Risk Act (SARA). More information about SARA, including how it protects individual species, is available in the Species at Risk Act: A Guide.

Provincial and Territorial Protection

To know if this species is protected by provincial or territorial laws, consult the provinces' and territories' websites.


Recovery Initiatives

Status of Recovery Planning

Recovery Strategies :

Name Recovery Strategy for the Western Silvery Aster (Symphyotrichum sericeum) in Canada
Status First posting on SAR registry


Recovery Team

Western Silvery Aster Recovery Team

  • Jennifer Chikoski - Chair/Contact - Government of Ontario
    Phone: 807-475-1732  Fax: 807-473-3023  Send Email
  • Hilary Gignac - Chair/Contact - Government of Ontario
    Phone: 807-475-1276  Fax: 807-473-3023  Send Email



PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.

2 record(s) found.

Recovery Strategies

Recovery Document Posting Plans

  • Environment and Climate Change Canada's Three-Year Recovery Document Posting Plan (2016)

    Environment and Climate Change Canada’s Three-Year Recovery Document Posting Plan identifies the species for which recovery documents will be posted each fiscal year starting in 2014-2015. Posting this three year plan on the Species at Risk Public Registry is intended to provide transparency to partners, stakeholders, and the public about Environment and Climate Change Canada’s plan to develop and post these proposed recovery strategies and management plans. However, both the number of documents and the particular species that are posted in a given year may change slightly due to a variety of circumstances. Last update March 31, 2017