Species At Risk

Forked Three-awned Grass

(Aristida basiramea)


Forked Three-awned Grass
Forked Three-awned Grass occurrences map


Forked Three-awned Grass is an annual plant that grows 30 to 50 centimetres tall. The leaves reach five to 15 centimetres in length, but only about one millimetre in width. Plants branch primarily at the base.

The bristle-like structures that are attached to its lemmas, the lower of the two modified leaves that enclose the flower, are called “awns”, giving the species part of its name. Forked Three-awned Grass is easiest to identify in September and October when the plants are well developed.


Forked Three-awned Grass is found primarily in the Midwestern United States, west from Colorado, south to Texas, east to Maine, and north to central Minnesota, northern Wisconsin and northern Michigan.

In Canada, Forked Three-awned Grass is found only in southwestern Quebec and southern Ontario, with one likely introduced population found in the Rainy River area of northwestern Ontario.


Forked Three-awned Grass grows on open, bare ground or in sparsely-covered grassy areas, often in bare spots between patches of other species of grasses. The maintenance of this type of habitat requires periodic disturbances, such as fire or drought, to prevent other plants from dominating the area. However, some forms of disturbance facilitate the establishment of invasive plant species that can outcompete Forked Three-awned Grass.


The main threat to Forked Three-awned Grass in Ontario is habitat loss and degradation. This occurs from development and fire suppression, which allows competing plants to flourish, including tree planting and the introduction of invasive plant species.


Forked Three-awned Grass and its habitat are protected under Ontario’s Endangered Species Act. It is also protected under the federal Species at Risk Act.

What You Can Do to Help the Forked Three-awned Grass

  • The Ministry of Natural Resources tracks species at risk such as Forked Three-awned Grass. 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 Forked Three-awned Grass on your property, you may be eligible for stewardship programs that support the protection and recovery of species at risk and their habitats.
  • Volunteer with your local nature club or provincial park to participate in surveys or stewardship work focused on species at risk.
  • 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?

In some cases, human activity has actually benefited this plant, since it depends on disturbances to maintain its open habitat. Other areas where its preferred habitat was once found have been planted with trees that have destroyed the habitat.

Did you know?

Seven populations of this plant were discovered by superimposing maps of shoreline bluffs from the end of the last ice age onto modern satellite imagery and then surveying rough, open fields, where these ancient shorelines once existed.

Did you know?

Since Forked Three-awned Grass is an annual, its growth and reproduction are influenced by each year’s environmental conditions. This makes estimating population size difficult, as a number of plants present in an area may remain relatively undetectable in the soil seed bank during any given year.

Did you know?

Most of the 250 to 300 members of this plant’s genus, Aristida, are found in warm-temperate to tropical climates.

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.