Species At Risk

Dense Blazing Star

(Liatris spicata)


Dense Blazing Star
Dense Blazing Star occurrences map


Dense Blazing Star is a beautiful perennial wildflower with stunning purple flowers. It can grow as tall as two metres. The stem is usually smooth with leaves arranged around it in a spiral. The flower heads have six to 10 disk flowers and are arranged in a long dense spike at the top of the plant. The seedpods are brown or black, small and somewhat tube-shaped. In the wild, thick patches of Dense Blazing Star give the landscape a rose-purple glow.


Dense Blazing Star is found only in North America. In Canada, it occurs naturally only in southwest Ontario, mainly in the area between Lake St. Clair, Lake Huron and Lake Erie. There are believed to be 11 to 13 populations in the province with six populations known to have been lost.


In Ontario, Dense Blazing Star grows in moist prairies, grassland savannahs, wet areas between sand dunes, and abandoned fields. This plant does not do well in the shade and is usually found in areas that are kept open and sunny by fire, floods, drought, or grazing.


The main threat to Dense Blazing Star is habitat loss due to urban development or habitat alteration. Another threat is natural succession, a process where trees and shrubs take over an area and eventually shade-out the sun-loving plants. The invasive plants, European Common Reed and Purple Loosestrife, are also a concern at some sites.


Dense Blazing Star is protected under Ontario’s Endangered Species Act and the federal Species at Risk Act.

What You Can Do to Help Dense Blazing Star

  • The Ministry of Natural Resources tracks species at risk such as Dense Blazing Star. You can use a handy online form to report your sightings to the Natural Heritage Information Centre. Photographs with specific locations or mapping coordinates are always helpful. nhic.mnr.gov.on.ca
  • Report any illegal activity related to plants and wildlife to 1-877-TIPS-MNR (847-7667).
  • Private land owners have a very important role to play in species at risk recovery. If you find Dense Blazing Star on your property, you may be eligible for stewardship programs that support the protection and recovery of species at risk and their habitats.
  • Dense Blazing Star and many other species at risk depend on healthy grassland prairies, a very rare habitat in Ontario. Learn more about these habitats, the species that depend on them, and what you can do to help at www.tallgrassontario.org.
  • Volunteer with your local nature club or provincial park to participate in surveys or stewardship work focused on species at risk.
  • Pollinators, such as bees, are in steep decline across the globe and they play a key role in the survival of many of Ontario’s rare plants. For information on how you can help scientists monitor pollinator populations in Ontario visit: www.seeds.ca/proj/poll.
  • Invasive species seriously threaten many of Ontario’s species at risk. To learn what you can do to help reduce the threat of invasive species, visit: ontario.ca/invasivespecies ; www.invadingspecies.com ; www.ontarioinvasiveplants.ca ; and, www.invasivespecies.gc.ca .

Did you know?

Dense Blazing Star is able to grow in soil that is contaminated with cadmium by turning this toxic heavy metal into a non-toxic form in its tissues.

Did you know?

Bees, butterflies and beetles are the main pollinators of Dense Blazing Star. You can help Ontario’s pollinators by planting insect-friendly plants such as milkweed, asters and goldenrod in your garden.

Did you know?

Wild fire has traditionally played an important role in maintaining the prairie habitat of Dense Blazing Star. Fire stimulates the growth of hardy prairie flowers while naturally removing trees and shrubs that would otherwise shade-out the sun-loving plants.

Did you know?

Aboriginal people have used Dense Blazing Star to treat colic, muscle pain, digestive issues and heart problems.

The Endangered Species Act

Contact your local ministry office

Often the best source of local information on species at risk is your nearest ministry office. Call with your questions or concerns.