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



The Lyall's Mariposa Lily is a long-lived perennial herb with a single, long, flat, basal leaf and a hairless stem measuring 10 to 30 cm, which grows each year from a subterranean bulb. Its purplish, bell-shaped flowers are composed of three fringed, lance-shaped petals and three sepals.


Distribution and Population

The species occurs along the eastern slope of the Cascade Mountains from extreme south central British Columbia to Yakima County in Washington state. The entire Canadian population occurs south of Richter Pass, between the Similkameen river and the Okanagan Valley, and is limited to a single height of land adjacent to the United States border. There are eleven known colonies, all so close together that they constitute only 3 or 4 effective populations. Most of these occur on provincial Crown Land on the upper slopes of Black Mountain.



Lyall’s Mariposa Lilies inhabit open grass-forb meadows within Douglas-fir forests at an elevation of 900 to 1300 m. Sites are dry and water-shedding, with low shrub cover. Summers are warm and dry and winters are cool, as a result of the rain shadow effect cast by the Coast-Cascade Mountains (coastal mountains intercept the clouds and rain advancing from the west, resulting in dry eastern slopes). This mariposa lily is shade intolerant. Disturbances, such as fires, may play a role in creating the natural forest openings it requires.



The Lyall's Mariposa Lily comes into bloom by June. The flowers are insect pollinated and self-compatible (produce seeds when self pollinated). The species reproduces solely by seed, which are poor dispersers. They are shed close to the parent plant in July and germinate the following spring. Adult plants alternate between reproductive and vegetative states. The foliage and fruit are browsed by insects and the bulbs are eaten by small mammals.



Silvicultural practices (especially the planting of coniferous tree seedlings in logged areas, including in areas that were natural meadow openings), excessive trampling and grazing by livestock, and invasion of habitat by exotic weeds threaten the species. Herbivory by insects and small mammals can also have a detrimental impact on populations. Finally, pollinator availability and poor seed dispersal are intrinsic biological limiting factors.



Federal Protection

More information about SARA, including how it protects individual species, is available in the Species at Risk Act: A Guide.

Of the eleven colonies found in British Columbia, two occur on private land, and the other nine are on provincial Crown Land administered by the British Columbia Ministry of Forests.

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