This Week’s Endangered Species in Focus: Large Whorled Pogonia (Isotria Verticillata)


The large-whorled pogonia was already assessed as endangered when the Endangered Species Act took effect in 2008.

What it looks like

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


The Large Whorled Pogonia (Isotria verticillata) is a tall (up to 40cm) orchid whose flower has greenish yellow petals and a white and crimson-purple “lip”. There are three long, narrow, dark purple sepals at the base of the flower. A short stalk or “peduncle” supports the orchid flower atop a whorl of five unstalked leaves at the summit of the plant’s smooth, hollow main stem. This species grows in acidic soils in moist deciduous or coniferous woods or in sphagnum bogs.

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.

Where it lives

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.


The Large Whorled Pogonia occurs from New England, southwestern Ontario and Michigan south to Texas and Florida.

In Canada, there are three records in southwestern Ontario.The site of its original 1879 discovery in Ontario apparently no longer exists. The species was considered extirpated (regionally extinct) for many years until discovered at a site in Haldimand-Norfolk in 1965. In addition to this site, it is known from two other southwestern Ontario locations, both discovered in the mid-1980’s

The last recorded sighting of Large Whorled Pogonia in Ontario was in 1996, when a single plant was found.

Threats: Although this species has a very restricted distribution at its northern range limits in Ontario, it is reasonable to suppose that some habitats were lost historically as a result of the removal of forest. This orchid is known for its tendency to enter a dormancy period, lasting for several years, after which numbers may reappear. Therefore, any site from which it disappears for no known reason should be monitored. Fire may help to stimulate flowering in this orchid. Attempts to grow the Large Whorled Pogonia from seed have met with little success, and it does not usually survive transplantation.

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.

Action we are taking

Endangered Species and their general habitat are automatically protected. The Large Whorled Pogonia is listed in regulation under Ontario’s Endangered Species Act, 2007, which protects the species and its habitat. The Natural Heritage component of the Provincial Policy Statement under the Planning Act provides for the protection of significant portions of the habitat of species listed in regulation under the E.S.A. One Ontario population of this orchid occurs in a protected area. Ontario’s Conservation Land Tax Incentive Program (CLTIP) will provide 100% tax relief to private landowners for the portion of their property (minimum size 0.5 acres) determined to be habitat of species in regulation under the E.S.A. The CLTIP program recognizes, encourages and supports private land stewardship. International trade in orchids or their parts is controlled under CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora).

Recovery strategy

A recovery strategy advises the ministry on ways to ensure healthy numbers of the species return to Ontario.

Government response statement

A government response statement outlines the actions the government intends to take or support to help recover the species.

What you can do


Report a Sighting

The Ministry of Natural Resources tracks species at risk such as the 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.


Volunteer with your local nature club or provincial park to participate in surveys or stewardship work focused on species at risk.

Private land owners have a very important role to play in species recovery. If you find large whorled pogonia on your land, you may be eligible for stewardship programs that support the protection and recovery of species at risk and their habitats.

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:


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:

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:

Report illegal activity

Report any illegal activity related to plants and wildlife to 1-877-TIPS-MNR (847-7667).

Quick facts

  • 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.
  • The seeds of Large Whorled Pogonia are dispersed by the wind.
  • Orchids can remain dormant in the soil before emerging when the conditions are suitable.

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