Photo of Four-leaved Milkweed
Photo: Sean Blaney,
Atlantic Canada Conservation Data Centre

Four-leaved Milkweed is a perennial herb of woodlands and forest edges that grows up to 80 cm in height, flowers from late May until the end of June, and is pollinated mostly by bees and butterflies. The species occurs in a provincially rare alvar habitat in Ontario and there are fewer than 200 known mature individuals.

Protecting and recovering Species at Risk in Ontario

Species at risk recovery is a key part of protecting Ontario’s biodiversity. Biodiversity – the variety of living organisms on Earth – provides us with clean air and water, food, fibre, medicine and other resources that we need to survive.

The Endangered Species Act, 2007 (ESA) is the Government of Ontario’s legislative commitment to protecting and recovering species at risk and their habitats. As soon as a species is listed as extirpated, endangered or threatened under the ESA, it is automatically protected from harm or harassment. Also, immediately upon listing, the habitats of endangered and threatened species are protected from damage or destruction.

Under the ESA, the Ministry of Natural Resources (the Ministry) must ensure that a recovery strategy is prepared for each species that is listed as endangered or threatened. A recovery strategy provides science-based advice to government on what is required to achieve recovery of a species.

Government response statements

Within nine months after a recovery strategy is prepared, the ESA requires the Ministry to publish a statement summarizing the government’s intended actions and priorities in response to the recovery strategy. The recovery strategy for Four-leaved Milkweed was published on December 7, 2011.

The response statement is the government’s policy response to the scientific advice provided in the recovery strategy. In addition to the strategy, the response statement is based on input from stakeholders, other jurisdictions, Aboriginal communities and members of the public. It reflects the best available traditional, local and scientific knowledge at this time and may be adapted if new information becomes available. In implementing the actions in the response statement, the ESA allows the Ministry to determine what is feasible, taking into account social and economic factors.

Moving forward to protect and recover Four-leaved Milkweed

Four-leaved Milkweed is listed as an endangered species under the ESA, which protects both the plant and its habitat. The ESA prohibits harm or harassment of the species and damage or destruction of its habitat without authorization. Such authorization would require that conditions established by the Ministry be met.

This globally secure species is found at the northern extent of its range in Ontario, alongside US populations in New York, Vermont, and New Hampshire. At present, populations of Four-leaved Milkweed are situated in Prince Edward County in the Bay of Quinte region. Four-leaved Milkweed occurs in alvar woodland communities, consisting of dry, shallow or rocky soils over limestone. Threats to the remaining Four-leaved Milkweed populations in Ontario include habitat loss and degradation due to residential and agriculture land uses, woody species succession, invasive species, and impacts from recreational activities.

The government’s goal for the recovery of Four-leaved Milkweed is to ensure the persistence of a self-sustaining population in Ontario.

Protecting and recovering species at risk is a shared responsibility. No single agency or organization has the knowledge, authority or financial resources to protect and recover all of Ontario’s species at risk. Successful recovery requires inter-governmental co-operation and the involvement of many individuals, organizations and communities.

In developing the government response statement, the Ministry considered what actions are feasible for the government to lead directly and what actions are feasible for the government to support its conservation partners to undertake.

Government-led actions

To help protect and recover Four-leaved Milkweed, the government will directly undertake the following actions:

  • Educate other agencies and authorities involved in planning and environmental assessment processes on the protection requirements under the ESA.
  • Encourage the submission of Four-leaved Milkweed data to the Ministry’s central repository at the Natural Heritage Information Centre.
  • Undertake communications and outreach to increase public awareness of species at risk in Ontario.
  • Protect Four-leaved Milkweed and its habitat through the ESA. Develop and enforce a regulation identifying the specific habitat of the species.
  • Support conservation, agency, municipal and industry partners and Aboriginal communities to undertake activities to protect and recover Four-leaved Milkweed. Support will be provided where appropriate through funding, agreements, permits (including conditions) and advisory services.
  • Establish and communicate annual priority actions for government support in order to encourage collaboration and reduce duplication of efforts.

Government-supported actions

The government endorses the following actions as being necessary for the protection and recovery of Four-leaved Milkweed. Actions identified as "high" will be given priority consideration for funding or for authorizations under the ESA. The government will focus its support on these high-priority actions over the next five years.

Focus area: Protection and Management

Objective: Protect existing populations and associated habitat and mitigate threats.


  1. (High) Develop and implement best management practices for alvar woodland communities that address known and potential threats, such as habitat loss and degradation due to residential and agriculture land uses, woody species succession, and invasive species.

Focus area: Research and Monitoring

Objective: Improve knowledge of Four-leaved Milkweed habitat, ecology, and threats.


  1. Develop and implement a standardized survey and monitoring program for Four-leaved Milkweed which includes:
    • conducting inventories of populations,
    • assessing habitat conditions of current populations, and
    • conducting further searches of suitable habitat for undiscovered populations.
  2. Prioritize and undertake research to address remaining questions regarding the species' ecology, including:
    • species demographics,
    • minimum viable population requirements, and
    • response to threats.

Implementing actions

Financial support for the implementation of actions may be available through the Species at Risk Stewardship Fund, Species at Risk Farm Incentive Program or Community Fisheries and Wildlife Involvement Program. Conservation partners are encouraged to discuss project proposals related to the actions in this response statement with the Ministry. The Ministry can also advise if any authorizations under the ESA or other legislation may be required to undertake the project.

Implementation of the actions may be subject to changing priorities across the multitude of species at risk, available resources and the capacity of partners to undertake recovery activities. Where appropriate, the implementation of actions for multiple species will be co-ordinated across government response statements.

Reviewing progress

The ESA requires the Ministry to conduct a review of progress towards protecting and recovering a species not later than five years from the publication of this response statement. The review will help identify if adjustments are needed to achieve the protection and recovery of Four-leaved Milkweed.


We would like to thank all those who participated in the development of the "Recovery Strategy for Four-leaved Milkweed in Ontario" for their dedication to protecting and recovering species at risk.