Species Profile

Slender Collomia

Scientific Name: Collomia tenella
Taxonomy Group: Vascular Plants
COSEWIC Range: British Columbia
COSEWIC Assessment Date and Status Change: November 2003
COSEWIC Status: Endangered
COSEWIC Status Criteria: B1ac(iv)+2ac(iv); D1
COSEWIC Reason for Designation: An annual herb present at a single sandy site near Princeton, British Columbia. The population fluctuates widely from year to year. At risk to stochastic events, roadside development, sand removal, and invasion by alien species.
COSEWIC History of Status Designation: Designated Endangered in November 2003.
SARA Status: Schedule 1, Endangered
Date of Listing (yyyy-mm-dd): 2005-07-14

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: | Description | Distribution and Population | Habitat | Biology | Threats | Protection | Recovery Initiatives | National Recovery Program | Documents


Slender Collomia is an annual herb. Its stem is freely branched, spreading at the base and sometimes ascending toward the tip, and may reach a height of 15 cm. The leaves are alternate, elongated and narrow, measuring 1 to 5 cm long and 1.5 mm wide. The pinkish to white flowers grow singly or in pairs at the forks of the branches, at the branch tips, or in the leaf axils, the angle where the leafstalk meets the stem. The corolla, consisting of all the petals, is five-lobed. The calyx, consisting of all the green sepals at the base of the flower, bows out and has small triangular teeth 1 to 2 mm long. The calyx also often has purplish knobs at the notches between the teeth. The fruit is a dry capsule containing a single seed. The seeds are sticky when wet.


Distribution and Population

The Slender Collomia ranges from southwestern British Columbia south into Oregon, Nevada, Utah and Wyoming in the United States. In Canada, the Slender Collomia has been observed only in the Similkameen River Valley, in the vicinity of Princeton, in southwestern British Columbia. In 2003, the only Canadian population of Slender Collomia comprised only 127 individuals distributed over an area of 56 m². At the time that this population was discovered in the Similkameen River Valley in 1997, it comprised only 10 individuals. In 2000, only one individual was observed, and in 2002, none. The plant reappeared in 2003 when environmental conditions were apparently more favourable. Since then, other sites in the area have been surveyed, but no Slender Collomia have been found.



The site where the Slender Collomia occurs in British Columbia consists of the eroded, steep, southeast-facing slopes of a ridge of fine sand. Approximately 20% of the site is covered in sparse vegetation, which consists of a variety of herbs and shrubs, with scattered specimens of Douglas-fir and ponderosa pine. There is a risk that invasive plants may propagate on this site, as has happened at several other locations in the vicinity, and thus reduce the area of the habitat suitable for this species.



There is little information on the biology of the Slender Collomia. Because this plant is an annual, it does not appear every year if environmental conditions are unfavourable. The Slender Collomia is thought to be capable of self-fertilization, meaning that the plant can fertilize its flowers with its own pollen, as is the case for other Collomia species. The seeds of this annual become sticky when wet, so they may be dispersed by animals. Because it is not known whether this species can disperse over long distances, the United States population, approximately 140 km away, cannot be counted upon to re-establish the population in British Columbia.



In British Columbia, the most immediate threat to the Slender Collomia comes from the very small size of its population and of the area that this population occupies. Together, these two factors make the population vulnerable to extirpation. In addition, because the habitats suited to this species are very limited in the south of the province, the opportunities for dispersal of seeds are also limited. The other main factors threatening the survival of the Slender Collomia in British Columbia are highway and residential construction, as well as invasive plants, which have already populated neighbouring habitats. All-terrain-vehicle traffic poses another threat to this species. The steep, unstable slopes where this herb grows are very fragile, but by the same token, they also present an attractive challenge to the drivers of these recreational vehicles. Lastly, weed-control activities that are mandatory under the Weed Control Act could affect this species indirectly, as the chemicals used to destroy nuisance plants are not very specific and could kill the Slender Collomia.



Federal Protection

The Slender Collomia 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.

The Slender Collomia is not protected by any provincial laws in British Columbia. However, the single population that has been observed in this province is located on a private property that is part of the province’s Agricultural Land Reserve and hence is protected from certain types of development. However, certain activities that might harm this species are not prohibited in the reserve, so that the Slender Collomia population that lives there is still endangered.

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 Multi-species Recovery Strategy for the Princeton Landscape, including Dwarf Woolly-heads (Psilocarphus brevissimus) Southern Mountain Population, Slender Collomia (Collomia tenella), and Stoloniferous Pussytoes (Antennaria flagellaris) in Canada
Status Final posting on SAR registry



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.

7 record(s) found.

COSEWIC Status Reports

  • COSEWIC assessment and status report on the slender collomia Collomia tenella in Canada (2003-11-01)

    Collomia tenella is an ascending to spreading, freely branched, annual, taprooted herb up to 15 cm tall. The leaves are alternate, linear, entire, 1-5 cm long and 1.5 mm wide. Flowers are single or in pairs at the branch tips, in the leaf axils or at the forks of the branches. The pinkish to white corollas are five-lobed. The calyces, which bow out and often form purplish knobs at the sinuses, have 1-2 mm long, triangular teeth. The seeds become sticky when moistened.

Response Statements

  • Response Statement - Slender Collomia (2004-10-22)

    An annual herb present at a single sandy site near Princeton, British Columbia. The population fluctuates widely from year to year. At risk to stochastic events, roadside development, sand removal, and invasion by alien species.

Recovery Strategies


  • Order Acknowledging Receipt of the Assessments Done Pursuant to Subsection 23(1) of the Act (2004-10-19)

    The Order acknowledges receipt by the Governor in Council of the assessments of the status of wildlife species done pursuant to 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 Schedules 1 to 3 to the Species at Risk Act (volume 139, number 15, 2005) (2005-07-27)

    The Minister of the Environment is recommending, pursuant to section 27 of the Species at Risk Act (SARA), that 43 species be added to Schedule 1, the List of Wildlife Species at Risk. This recommendation is based on scientific assessments by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) and on consultations with governments, Aboriginal peoples, wildlife management boards, stakeholders and the Canadian public.

COSEWIC Annual Reports

  • COSEWIC Annual Report - 2004 (2004-09-16)

    2004 Annual Report to 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: November 2004 (2004-11-23)

    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.
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