Species Profile

Slender Popcornflower

Scientific Name: Plagiobothrys tenellus
Taxonomy Group: Vascular Plants
COSEWIC Range: British Columbia
COSEWIC Assessment Date and Status Change: November 2008
COSEWIC Status: Threatened
COSEWIC Status Criteria: B1ab(iii)+2ab(iii); D1
COSEWIC Reason for Designation: An annual herb of grassy slopes and coastal bluffs within the highly reduced and fragmented Garry Oak ecosystem. About half of the known populations have been extirpated from areas heavily impacted by invasive alien plants on southeastern Vancouver Island and adjacent Gulf Islands. Only seven small populations remain. Population sizes fluctuate, likely depending on precipitation, with several comprising only a few individuals. The total population size is estimated to be fewer than 1000 individuals. Invasive plants continue to degrade the species’ habitat at all sites.
COSEWIC History of Status Designation: Designated Threatened in November 2008.
SARA Status: Schedule 1, Threatened
Date of Listing (yyyy-mm-dd): 2011-02-04

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 | Habitat | Biology | Threats | Protection | Recovery Initiatives | Recovery Team | National Recovery Program | Documents

Description

Slender Popcornflower is an annual with a single or branched stem 5 to 25 cm tall. It has leaves at the base that occur in a rosette and leaves on the stem that are alternate and reduced upwards. The stem leaves are few and covered with hairs that lie flat. The small flowers are arranged in a coiled inflorescence at the tip of the stem. The petals are white and fused at the base, flaring above into five lobes. The fruits, which are 1.5 to 2.5mm in length, look like small cross-shaped nuts covered with rows of warts. In Canada, Slender Popcornflower is easily distinguished from Scouler’s Popcornflower and Fragrant Popcornflower by the presence of a rosette of leaves and the shape of its fruits.

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Distribution and Population

Slender Popcornflower occurs mostly on the east side of the Cascade Mountains from southwestern British Columbia south to southern California and Nevada. In British Columbia, the populations are found on southeastern Vancouver Island and adjacent Gulf Islands. Slender Popcornflower has been reported from 13 locations in Canada, with 7 of these considered extant. The Canadian populations are separated by distances of 10 to 15 km. There are presumed to be six extant populations of Slender Popcornflower on the Gulf Islands and one on southeastern Vancouver Island. The most recent surveys indicate that there were a total of between 400 and 800 individuals in these small populations in 2007. Even if viable seeds for this annual species are still present in the soil, the total number of individuals that could potentially develop in a favourable year for growth is likely well below 2500. The species is known to have declined substantially in the past, since the six populations reported before 1958 are now extirpated. However, current population trends are not well known because few sites have been visited more than once. Certain observations suggest that this annual species undergoes considerable fluctuation in population size, likely depending on precipitation. The Vancouver Island population, the only one that has been visited repeatedly, either fluctuates at low numbers or is in fact declining.

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Habitat

In British Columbia, the populations of Slender Popcornflower are found in the Garry Oak ecosystem. This small area has a Mediterranean climate, with mild, wet winters and warm, dry summers. The species occurs on coastal bluffs and other dry grassy slopes that are usually steep, open and south- or southwest-facing. It is often found in gravelly or rocky soils. Although there are no specific data on the trends for the Canadian habitat for Slender Popcornflower, it likely follows the same trends as those for the Garry Oak ecosystem, which has declined to less than 5% of its original extent in the Victoria area and is now limited to small isolated pockets.

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Biology

No research has been conducted on Slender Popcornflower. It is known, however, that the species is an annual and that flowers are hermaphrodite, with both male and female organs. As in other popcornflower species, flowers are likely fertilized by insects with pollen from nearby flowers. Flowering has been observed from late April to late May in British Columbia, with seed production occurring in June. Each flower produces up to four small, hard one-seeded fruits, or nutlets. On a local basis, dispersal is probably by small mammals and by gravity, while birds are likely the active, long-range dispersers.

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Threats

The most obvious threat to Slender Popcornflower in British Columbia is habitat destruction through housing development on private property. Six of the seven extant Canadian populations occur on the Gulf Islands, which are now experiencing increasing housing development. All but one of the populations in the densely populated Victoria area are now considered extirpated, likely due to habitat destruction through urban development. Another major threat is introduced plant species, which have invaded and altered much of the habitat of Slender Popcornflower. These invasive species may be contributing to the decline in observed Slender Popcornflower numbers since 1998 by increasing competition and decreasing soil moisture. Increased development on both the Gulf Islands and Vancouver Island has fragmented the habitat into small pockets, limiting the ability of the species to become established in new locations or re-establish extirpated populations. Fire suppression and grazing by livestock likely also affected Slender Popcornflower populations. Fire suppression may have resulted in increased thatch build-up, and afforestation and grazing could have altered soil properties and encouraged non-native and weedy species. Ongoing grazing by feral goats at the Saturna Island site has likely resulted in soil erosion and increased competition from weedy introduced plants.

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Protection

Federal Protection

The Slender Popcornflower 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.

Slender Popcornflower is not protected by any provincial legislation in British Columbia. However, the Saturna Island population is protected under the Canada National Parks Act because it is located within the Gulf Islands National Park Reserve of Canada. British Columbia’s Park Act protects the population located within a provincial park on Galiano Island, while the southeastern Vancouver Island location is in a regional park, where it could receive some level of protection.

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 Slender Popcornflower (Plagiobothrys tenellus) in Canada
Status First posting on SAR registry

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Recovery Team

Garry Oak Ecosystems Recovery Team

  • Conan Webb - Chair/Contact - Parks Canada
    Phone: 250-478-5153  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.

12 record(s) found.

Reports on the Progress of Recovery Document Implementation

COSEWIC Status Reports

  • COSEWIC Assessment and Status Report on the Slender Popcornflower Plagiobothrys tenellus in Canada (2009-08-28)

    Slender Popcornflower Plagiobothrys tenellus is a member of a genus of approximately 50 species in the borage family (Boraginaceae). Species of the genus are found mainly in North America, but also occur in South America and Australia. Three species occur in Canada. Slender Popcornflower is an annual growing from a slender taproot. The plant has a single or sometimes branched stem 5-25 cm tall. The basal leaves occur in a rosette and the stem leaves are few, alternate, and reduced upwards. The flowering stems have coiled, terminal inflorescences with small flowers. The petals are white, fused at the base and flare above into 5 lobes. The nutlets are cross-shaped and warty.

Response Statements

  • Response Statement - Slender Popcornflower (2009-11-25)

    An annual herb of grassy slopes and coastal bluffs within the highly reduced and fragmented Garry Oak ecosystem. About half of the known populations have been extirpated from areas heavily impacted by invasive alien plants on southeastern Vancouver Island and adjacent Gulf Islands. Only seven small populations remain. Population sizes fluctuate, likely depending on precipitation, with several comprising only a few individuals. The total population size is estimated to be fewer than 1000 individuals. Invasive plants continue to degrade the species’ habitat at all sites.

Recovery Strategies

  • Recovery Strategy for the Slender Popcornflower (Plagiobothrys tenellus) in Canada (2014-09-17)

    The Canadian population of Slender Popcornflower (Plagiobothrys tenellus) was assessed as Threatened in 2008 by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). The population was listed as Threatened under Canada`s Species at Risk Act (SARA) in February 2011. Slender Popcornflower is a small annual plant that grows in exposed soils on dry, steep, south facing grassy slopes and coastal bluffs. Its range is restricted to North America, mostly on the east side of the Cascade Mountains, through Washington, Idaho, Oregon, Utah, Nevada, and southern California. Isolated patches are found on southeast Vancouver Island (near Victoria), the Gulf Islands, and San Juan Islands. Seven populations are still considered extant in Canada, but only one of these has been observed in the last decade. The Canadian population of Slender Popcornflower comprises

Action Plans

  • Multi-species Action Plan for Gulf Islands National Park Reserve of Canada (2018-08-01)

    The Multi-species Action Plan for Gulf Islands National Park Reserve of Canada applies to lands and waters occurring within the boundaries of Gulf Islands National Park Reserve (GINPR). The plan meets the requirements for action plans set out in the Species at Risk Act (SARA (s.47)) for species requiring an action plan that regularly occur at this site. Measures described in this plan will also provide benefits to other species of conservation concern that regularly occur at GINPR.

Critical Habitat Statements

Orders

COSEWIC Annual Reports

  • COSEWIC Annual Report - 2009 (2009-08-28)

    2009 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.

Permits and Related Agreements

  • Explanation for issuing permit(#FRH-2016-21599-SARA ), persuant to the provisions of section 74 of SARA (2016-06-01)

    Parks Canada will collect seeds or other propagules, grow plants in a nursery, prepare and maintain translocation sites and out-plant the resulting stock to suitable sites at Gulf Islands National Park Reserve and or Fort Rodd Hill National Historic Site to increase populations of a number of species at risk in coastal sand dune and Garry Oak ecosystems, as per the recovery strategies for the species.
  • Explanation for issuing permit(#GINP-2020-37539), persuant to the provisions of section 74 of SARA (2020-04-01)

    This is a conservation and restoration project for species at risk at the Parks Canada Coastal British Columbia Field Unit. The project aims to increase the supply of propagative material for a number of plant species at risk within the field unit; implement recovery actions outlined in Parks Canada's multi-species action plans for Gulf Islands National Park Reserve and Fort Rodd Hill National Historic Site; and improve knowledge on the best practices for the propagation, enhancement, translocation and habitat management of these species at risk. Propagative material (seed and rhizome) will be collected from species at risk in Gulf Islands National Park Reserve from May through October and will be sown outdoors in the Fort Rodd Hill National Historic Site conservation nursery from September through March. Propagative material from Coastal Scouler's Catchfly and Golden Paintbrush will be collected from populations on Mini D'Arcy Islet. Propagative material from Contorted-pod Evening-primrose will be collected from the population on Sidney Island. Contorted-pod Evening primrose may be affected by some localized trampling of the species and Common Nighthawk may be flushed from their nests. This project specifically addresses the species threats outlined in the recovery strategies and is believed necessary to secure the persistence of these plant species in Canada.

Consultation Documents

  • Consultation on Amending the List of Species under the Species at Risk Act: Terrestrial Species, December 2009 (2009-12-17)

    As part of its strategy for protecting wildlife species at risk, the Government of Canada proclaimed the Species at Risk Act (SARA) on June 5, 2003. Attached to the Act is Schedule 1, the list of the species that receive protection under SARA, also called the List of Wildlife Species at Risk. Please submit your comments by March 1, 2010 for species undergoing normal consultations and by March 1, 2011 for species undergoing extended consultations.
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