Species Profile

Western Silvery Aster

Scientific Name: Symphyotrichum sericeum
Other/Previous Names: Western Silver-leaved Aster,Virgulus sericeus
Taxonomy Group: Vascular Plants
COSEWIC Range: Manitoba, Ontario
COSEWIC Assessment Date and Status Change: May 2021
COSEWIC Status: Threatened
COSEWIC Status Criteria: A3c+4ac
COSEWIC Reason for Designation: This species is a beautiful, purple-flowered perennial with silky silvery leaves, that is restricted to isolated remnant xeric tall-grass prairie and oak savannah in southern Manitoba and northwestern Ontario. This species was designated Threatened at the last assessment because of the small number of known individuals. Subsequent search effort has resulted in the discovery of new sites and partnerships with public and private land managers have increased the population at some sites. However, there have been declines in abundance and area of occupancy elsewhere and threats to this species remain very high, primarily from aggregate extraction and habitat degradation. A population decline of greater than 30 percent is suspected within the next 20-30 years based on potential threat impacts. The species is limited by low seed viability coupled with low seed set, indicating that current declines could continue.
COSEWIC History of Status Designation: Designated Special Concern in 1988. Status re-examined and designated Threatened in May 2000. Status re-examined and confirmed in May 2021.
SARA Status: Schedule 1, Threatened
Date of Listing (yyyy-mm-dd): 2003-06-05

Please note that this information is provided for general information purposes only. For the most up to date and accurate list of species listed under the Species at Risk Act, please see the Justice Laws Website.

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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

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Description

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.

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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.

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Habitat

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.

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Biology

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.

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Threats

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.

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Protection

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.

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Recovery Initiatives

Status of Recovery Planning

Recovery Strategies :

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

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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

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Documents

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.

5 record(s) found.

Response Statements

  • Response Statement - Western Silvery Aster (2022-01-10)

    This species is a beautiful, purple-flowered perennial with silky silvery leaves, that is restricted to isolated remnant xeric tall-grass prairie and oak savannah in southern Manitoba and northwestern Ontario. This species was designated Threatened at the last assessment because of the small number of known individuals. Subsequent search effort has resulted in the discovery of new sites and partnerships with public and private land managers have increased the population at some sites. However, there have been declines in abundance and area of occupancy elsewhere and threats to this species remain very high, primarily from aggregate extraction and habitat degradation. A population decline of greater than 30 percent is suspected within the next 20-30 years based on potential threat impacts. The species is limited by low seed viability coupled with low seed set, indicating that current declines could continue.

Recovery Strategies

COSEWIC Annual Reports

  • COSEWIC Annual Report 2020 to 2021 (2021-10-12)

    Over the past year COSEWIC assessed a total of 66 wildlife species, of which 4 were assigned a status of Not at Risk. Of these 66, COSEWIC re-examined the status of 41 wildlife species; of these, 80% were reassessed at the same or lower level of risk. To date and with the submission of this report, COSEWIC’s assessments now include 826 wildlife species in various risk categories including 369 Endangered, 196 Threatened, 239 Special Concern, and 22 Extirpated (i.e. no longer found in the wild in Canada). In addition, 19 wildlife species have been assessed as Extinct, 62 wildlife species have been designated as Data Deficient, and 202 have been assessed as Not at Risk.

Consultation Documents

  • Consultation on Amending the List of Species under the Species at Risk Act: Terrestrial Species January 2022 (2022-01-10)

    The Government of Canada is committed to preventing the disappearance of wildlife species at risk from our lands. As part of its strategy for realizing that commitment, on June 5, 2003, the Government of Canada proclaimed the Species at Risk Act (SARA). Attached to the Act is Schedule 1, the list of the species provided for under SARA, also called the List of Wildlife Species at Risk. Extirpated, Endangered and Threatened species on Schedule 1 benefit from the protection afforded by the prohibitions and from recovery planning requirements under SARA. Special Concern species benefit from its management planning requirements. Schedule 1 has grown from the original 233 to 640 wildlife species at risk. Please submit your comments by May 10, 2022, for terrestrial species undergoing normal consultations and by October 10, 2022, for terrestrial species undergoing extended consultations. For a description of the consultation paths these species will undergo, please visit the Species at Risk (SAR) Public Registry website at: The Minister of the Environment's Response to Species at Risk Assessments.

Recovery Document Posting Plans

  • Environment and Climate Change Canada's Three-Year Recovery Document Posting Plan (2016-07-06)

    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 December 2, 2021
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