Species Profile

Short-rayed Alkali Aster

Scientific Name: Symphyotrichum frondosum
Taxonomy Group: Vascular Plants
Range: British Columbia
Last COSEWIC Assessment: April 2006
Last COSEWIC Designation: Endangered
SARA Status: Schedule 1, Endangered

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Quick Links: | Description | Habitat | Biology | Threats | Protection | Recovery Initiatives | Recovery Team | National Recovery Program | Documents

Image of Short-rayed Alkali Aster


The Short-rayed Alkali Aster is a small annual herb, 5 to 60 cm tall, with many branches. It usually grows flat on the ground but can be erect. Its small flowers are clustered in numerous flower heads, and the heads resemble individual flowers. The heads have small green leaves, called bracts, arranged at the base of the head in a receptacle. The centre of the flower head is composed of small yellow flowers, similar to a daisy, and is surrounded by white or pink threadlike flowers. Plants are generally submersed until late summer, with flowering occurring in August and early September, when the water draws down. A similar species, the rayless alkali aster, can be distinguished from the Short-rayed Alkali Aster by its lack of ray petals dividing the heads.


Distribution and Population

The Short-rayed Alkali Aster is known from Mexico, the United States and Canada. In the United States, it is found in California, Arizona, New Mexico, Nevada, Colorado, Idaho, Montana, Utah, Oregon, Washington and Wyoming. In Canada, it is known only from British Columbia, primarily in the southern Okanagan Valley. The species has been confirmed at four locations: the shores of Osoyoos Lake, the shores of Vaseux Lake, the shores of Skaha Lake and the shores of Max Lake (Penticton). The Osoyoos Lake site supports four sub-populations: one confirmed sub-population, one extirpated sub-population and two unconfirmed sub-populations. An ephemeral disjunct population was reported from Surrey, along the shore of the Fraser River. This site is now extirpated, but this indicates that the species most likely occurs upstream in the Fraser-Thompson drainage basin. Since the abundance of the Short-rayed Alkali Aster fluctuates with annual climatic variation and water levels, observations from single years do not provide a true picture of the species. In addition, the limited data available for each of the four known locations are insufficient to allow trends for this population to be determined.



In Canada, the Short-rayed Alkali Aster has been reported primarily from lakeshore habitats in moist drawdown zones of sandy beaches and the perimeters of alkali lakes and ponds in the southern Okanagan Valley, in British Columbia. In these sites, the water draws down in the late summer and early fall, exposing shallowly sloping moist sites suitable for flowering and seed dispersal. As with other beach sites, heavy beach use and beach maintenance at certain sites have no doubt resulted in habitat degradation.



There is little information on the biology of the Short-rayed Alkali Aster. Based on a few observations, flowering time in British Columbia is from late July to early October. The species appears to be capable of self-fertilization. The adaptability of this aster is unknown; however, three populations occur on heavily used and managed beaches. While it is more abundant in the less trampled areas, it clearly can persist even with some trampling. This shoreline species is also adapted to fluctuating water levels and late summer drawdown. This species can resist high pH and high salinity, but it prefers moist habitats. The dispersal mechanisms of the Short-rayed Alkali Aster are unknown, but dispersal likely occurs by water, waterfowl and wind, in common with other aster species. The observation of a disjunct population in Surrey suggests that long-distance dispersal occurs.



Currently, beach management activities represent a major threat to this species at three sites. These activities, which are carried out in order to maintain the beach for swimming, include roto-tilling, sand sifting, lawn mowing and beach cleaning. Heavy beach use is another major threat to these small populations. Use of the beach habitat by swimmers, boaters and children (digging in the sand, boat launching and storage, trampling and compaction) has a direct impact on this species’ habitat. Invasive plants may pose another serious threat. Finally, like all smaller and fragmented populations of a rare species, populations of the Short-rayed Alkali Aster face the problems inherent in these situations, including the potential for catastrophic loss.



Federal Protection

The Short-rayed Alkali 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.

In British Columbia, the Short-rayed Alkali Aster is not protected under any provincial statute. However, two populations occur, entirely or in part, within provincial parks, where they are protected. Under the British Columbia Parks Act, picking the species is prohibited in a provincial park.

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 Short-rayed Alkali Aster (Symphyotrichum frondosum) in Canada
Status Final posting on SAR registry


Recovery Team

Team for Short-rayed Alkali Aster

  • Brenda Costanzo - Chair/Contact - Government of BC
    Phone: 250-387-9611  Fax: 250-356-9145  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.

8 record(s) found.

COSEWIC Status Reports

  • COSEWIC assessment and status report on the short-rayed alkali aster Symphyotrichum frondosum in Canada (2006)

    The short-rayed alkali aster, Symphyotrichum frondosum, is a late emergent shoreline species reported primarily from lakeshore habitats in moist drawdown zones of sandy beaches and perimeters of alkali lakes and ponds in British Columbia. It is found primarily in the bunchgrass biogeoclimatic zone (Douglas et al. 1998) of the sagebrush steppe in the southern Okanagan Valley. A single ephemeral population in sand dredgings on the shore of the Fraser River in Surrey may represent the presence of the species upstream in the Fraser-Thompson drainage.

COSEWIC Assessments

Response Statements

  • Response Statements - Short-rayed Alkali Aster (2006)

    An annual herb of lake shorelines present at only a few remaining sites in restricted habitats. The small populations are subject to disruption from such activities as trampling, beach management, spread of invasive plants and potential development of a major facility at one of the primary sites.

Recovery Strategies

  • Recovery Strategy for the Short-rayed Alkali Aster (Symphyotrichum frondosum) in Canada (2013)

    Short-rayed Alkali Aster is an annual late summer flowering species reported in British Columbia from lakeshores and pond margins in the Okanagan Valley. It was listed as Endangered under the Species at Risk Act (SARA) in 2007. Environment Canada (EC) is the lead federal department under SARA, but the province of British Columbia is the responsible jurisdiction for the management of this species and is the lead for recovery planning under the Accord for the Protection of Species at Risk. A provincial recovery strategy for the species was developed on behalf of province of British Columbia in 2009. EC is adopting the provincial recovery strategy under section 44 of SARA and has included a federal addition to complete the SARA requirements. The federal addition and the provincial recovery strategy together constitute the federal recovery strategy for the Short-rayed Alkali Aster. It has been prepared in cooperation with the province of British Columbia and the Department of Fisheries and Oceans.


  • Order Acknowledging Receipt of the Assessments Done Pursuant to Subsection 23(1) of the Act (2007) (2007)

    This Order acknowledges receipt by the Governor in Council of the assessments of the status of 40 species done pursuant to paragraph 15(1)(a) and in accordance with subsection 23(1) of the Species at Risk Act (SARA) by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). The purpose of SARA is to prevent wildlife species from being extirpated or becoming extinct, to provide for the recovery of wildlife species that are extirpated, endangered or threatened as a result of human activity and to manage species of special concern to prevent them from becoming endangered or threatened.
  • Order Amending Schedule 1 to the Species at Risk Act (2007)

    Her Excellency the Governor General in Council, on the recommendation of the Minister of the Environment, pursuant to section 27 of the Species at Risk Act, hereby makes the annexed Order Amending Schedules 1 to 3 to the Species at Risk Act.

COSEWIC Annual Reports

  • COSEWIC Annual Report - 2006 (2006)

    2006 Annual Report to the The Minister of the Environment and the Canadian Endangered Species Conservation Council (CESCC) from the Committee on the Status of Endangered Wildlife in Canada.

Consultation Documents

  • Consultation on Amending the List of Species under the Species at Risk Act Terrestrial Species: December 2006 (2006)

    The Government of Canada proclaimed the Species at Risk Act (SARA) on June 5, 2003 as part of its strategy for the protection of wildlife species at risk. Attached to the Act is Schedule 1, the list of the species that receive protection under SARA, hereinafter referred to as the 'SARA list'. Canadians are invited to comment on whether all or some of the species included in this document should be added to the SARA list. Please submit your comments by March 16, 2007 for species undergoing normal consultations and by March 14, 2008 for species undergoing extended consultations.