Species At Risk

Large Whorled Pogonia

(Isotria verticillata)


Large Whorled Pogonia
Large Whorled Pogonia occurrences map


Large Whorled Pogonia is a member of the orchid family. This small and inconspicuous plant reaches about 30 centimetres in height.

Large Whorled Pogonia flowers from late May to early June, producing a single yellowish-green flower just above a whorl of five to six leaves. The flower is mildly fragrant and is pollinated mainly by bees. The seeds require the presence of specific fungi to germinate.

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Large Whorled Pogonia ranges from New England and Michigan south to Texas and Georgia. In Canada, there are three records in southwestern Ontario. The last recorded sighting of Large Whorled Pogonia in Ontario was in 1996, when a single plant was found.


In Ontario, Large Whorled Pogonia has been found in deciduous or mixed forests with sandy soil and a thick layer of leaf litter. A relatively open forest canopy is required so that enough light can reach the plant.


Excessive shade, invasive species such as exotic earthworms and Garlic Mustard, changes in water levels such as flooding, soil compaction, trampling and loss of the soil fungi depend on for survival, are all likely contributors to the decline or loss of this species at sites in Ontario.


Large Whorled Pogonia is protected under Ontario’s Endangered Species Act and the federal Species at Risk Act.

What You Can Do to Help Large Whorled Pogonia

  • The Ministry of Natural Resources tracks species at risk such as Large Whorled Pogonia. 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 Large Whorled Pogonia 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.
  • 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.
  • The Carolinian forests of southern Ontario support an amazing diversity of plants and wildlife, including many species at risk. Carolinian Canada is working to help recover species at risk and their habitats. For more information, visit: www.carolinian.org/SpeciesHabitats.htm.
  • 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?

As do all orchids, Large Whorled Pogonia has a symbiotic relationship with fungus found in the soil, which means they are interdependent for nourishment and survival. The Large Whorled Pogonia will only produce seeds if the necessary fungus is present in the soil.

Did you know?

The seeds of Large Whorled Pogonia are dispersed by the wind.

Did you know?

Orchids can remain dormant in the soil before emerging when the conditions are suitable.

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.