Species Profile

Lyall's Mariposa Lily

Scientific Name: Calochortus lyallii
Taxonomy Group: Vascular Plants
Range: British Columbia
Last COSEWIC Assessment: May 2011
Last COSEWIC Designation: Special Concern
SARA Status: Schedule 1, Special Concern

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

Image of Lyall's Mariposa Lily

Lyall's Mariposa Lily Photo 1



Lyall’s Mariposa Lily (Calochortus lyallii) is a bulbous perennial herb in the lily family. Important diagnostic features include white to purplish-tinged petals with fringed margins and crescent-shaped glands, differentiated sepals, and erect capsules. (Updated 2017/05/25)


Distribution and Population

Lyall’s Mariposa Lily occurs along the eastern slope of the Cascade Mountains from extreme south-central British Columbia to Yakima Co., Washington. Canadian populations are known only from highlands west of Osoyoos, adjacent to the U.S. border. (Updated 2017/05/25)



The species occurs on well-drained soils in sagebrush grasslands and grassy forest openings between 900 m and 1300 m elevation. (Updated 2017/05/25)



Lyall’s Mariposa Lily is a long-lived perennial that emerges each year from a subterranean bulb and reproduces exclusively by seed. Generation time is estimated as 15 years. Flowers are insect-pollinated, and capable of outcrossing and selfing. Seeds are shed in the summer and germinate close to the parent plant the following spring. Mature plants can alternate over time between reproductive (flowering) and vegetative (non-flowering) states. Bulbs have the ability to remain dormant underground for over three years, although dormancy episodes typically last a single year. Herbage and fruits are browsed by insects and bulbs are browsed by small mammals. (Updated 2017/05/25)



Establishment of the South Okanagan Grasslands Protected Area (by the BC Ministry of Environment) in 2001 and subsequent management actions have substantially reduced anthropogenic threats (e.g., from silvicultural practices and overgrazing) at the largest location, which encompasses 3 of 5 populations, and more than 85% of known individuals. Threats from invasive alien plant species, livestock trampling, and forest ingrowth still exist at this location, but do not appear imminent. The remaining two populations are on private land and are each treated as locations. The threats from silviculture and grazing at these sites may persist, and have the greatest potential to result in declines at these locations. Observed fluctuations in the number of mature individuals are not well understood, but may be part of the natural cycle for this species. Fluctuations of these magnitudes represent a potential limiting factor for the persistence of subpopulations, but as these do not appear related to human activity, and appear to be mitigated by persistence of dormant individuals, they are not considered extreme fluctuations by COSEWIC definitions. Currently, stochastic factors such as a long fire interval, unfavourable climatic conditions, and high rates of herbivory by small mammals may be combining to limit population size. Poor seed dispersal is an intrinsic limiting factor. (Updated 2017/05/25)



Federal Protection

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 Lyall's Mariposa Lily Recovery Strategy
Status Submitted for peer review/ review by F/P/T partners



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.

9 record(s) found.

COSEWIC Status Reports

COSEWIC Assessments

Response Statements

  • Response Statement - Lyall's Mariposa Lily (2011)

    This species is a distinctive, long-lived perennial with a small range in Canada. It is known from only 5 populations in forest openings and sagebrush grasslands in southern BC, near Osoyoos.  Plants emerge from underground bulbs in late spring, but are capable of remaining dormant for one or more years. This plant was formerly designated Threatened, but most of the area where it occurs has been designated as a provincial protected area, and the main threats, related to grazing and forest management, have now been mitigated.

Management Plans

  • Management Plan for the Lyall’s Mariposa Lily (Calochortus lyallii) in Canada (2017)

    The Minister of Environment and Climate Change is the competent minister under SARA for the Lyall’s Mariposa Lily and has prepared the federal component of this management plan (Part 1), as per section 65 of SARA. To the extent possible, it has been prepared in cooperation with the B.C. Ministry of Environment, as per section 66(1) of SARA. SARA section 69 allows the Minister to adopt all or part of an existing plan for the species if the Minister is of the opinion that an existing plan relating to wildlife species includes adequate measures for the conservation of the species. The Province of British Columbia provided the attached management plan for the Lyall’s Mariposa Lily (Part 2) as science advice to the jurisdictions responsible for managing the species in British Columbia. It was prepared in cooperation with Environment and Climate Change Canada.


  • Order Acknowledging Receipt of the Assessments Done Pursuant to Subsection 23(1) of the Act (2016)

    His Excellency the Governor General in Council, on the recommendation of the Minister of the Environment, acknowledges receipt, on the making of this Order, of assessments conducted under subsection 23(1) of the Species at Risk Act by the Committee on the Status of Endangered Wildlife in Canada with respect to the species set out in the annexed schedule.
  • Order Amending Schedule 1 to the Species at Risk Act (2017)

    His Excellency the Governor General in Council, on the recommendation of the Minister of the Environment, pursuant to subsection 27(1) of the Species at Risk Act, makes the annexed Order Amending Schedule 1 to the Species at Risk Act.

COSEWIC Annual Reports

  • COSEWIC Annual Report - 2010 - 2011 (2011)

    Under Canada’s Species at Risk Act (SARA), the foremost function of COSEWIC is to “assess the status of each wildlife species considered by COSEWIC to be at risk and, as part of the assessment, identify existing and potential threats to the species”. COSEWIC held two Wildlife Species Assessment Meetings during the past year assessing the status or reviewing the classification of a total of 92 wildlife species.

Consultation Documents

  • Consultation on Amending the List of Species under the Species at Risk Act: Terrestrial Species – December 2011 (2011)

    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 February 8, 2012 for species undergoing normal consultations and by November 8, 2012 for species undergoing extended consultations.

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