Large Whorled Pogonia
Scientific Name: Isotria verticillata
Taxonomy Group: Vascular Plants
COSEWIC Range: Ontario
COSEWIC Assessment Date and Status Change: November 2011
COSEWIC Status: Endangered
COSEWIC Status Criteria: B1ab(iii)+2ab(iii); D1
COSEWIC Reason for Designation:
This orchid is known historically from only 3 sites in Ontario, but it has not been seen since 1996 despite searches at two of the three previously known sites. The species requires rich, deciduous or mixed, moist forest on sandy soil with abundant humus; this habitat continues to decline in quality due to trampling and exotic plants and earthworms. It is possible that this species may still be extant in Canada since many orchids are known to have long dormancy periods and often occur in very low numbers.
COSEWIC History of Status Designation: Designated Endangered in April 1986. Status re-examined and confirmed Endangered in April 1998, May 2000, and November 2011.
SARA Status: Schedule 1, Endangered
Date of Listing (yyyy-mm-dd): 2003-06-05
Please note that this information is provided for general information purposes only. For the most up to date and accurate list of species listed under the Species at Risk Act, please see the Justice Laws Website.
Image of Large Whorled Pogonia
Large Whorled Pogonia (Isotria verticillata) is an orchid that has a single whorl of five to six leaves at the top of the stem. The leaves may be overtopped by a single yellowish-green flower. The five narrow, purplish sepals are much longer than the petals. (Updated 2017/05/23)
Distribution and Population
The orchid occurs in the United States from New England and Michigan south to Texas and Georgia. Its only Canadian occurrence is in southwestern Ontario. In 1986, the orchid was known at two sites. Since that time it seems to have disappeared at one of the sites and only one plant has been seen at the other site. A third station was found after the status report was written; however, it seems to have been eliminated recently. (Updated 2017/05/23)
This plant requires rich, moist, deciduous or mixed forest on sandy soil with a thick leaf litter, lots of humus, and a relatively open canopy. (Updated 2017/05/23)
Large Whorled Pogonia is a relatively small and inconspicuous plant that is very similar to non-flowering shoots of the common Indian Cucumber-root (Medeola virginiana). This similarity could cause the orchid to be trampled inadvertently by those trying to find the species. (Updated 2017/05/23)
The main limiting factor is the lack of suitable mixed forest habitat with an acidic substrate in the heavily developed Carolinian Zone of southwestern Ontario. The species is at risk from trampling by those who would like to find or photograph this rare orchid. (Updated 2017/05/23)
The Large Whorled Pogonia is protected under the federal Species at Risk Act (SARA). More information about SARA, including how it protects individual species, is available in the Species at Risk Act: A Guide.
Provincial and Territorial Protection
Status of Recovery Planning
Recovery Strategies :
Name Recovery Strategy for the Large Whorled Pogonia (Isotria verticillata) in Canada
Status Final posting on SAR registry
Carolinian Woodland Plants Recovery Team
Jarmo Jalava - Chair/Contact - Other
Phone: 705-760-2823 Send Email
PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.
6 record(s) found.
- COSEWIC Status Reports (1 record(s) found.)
- Response Statements (1 record(s) found.)
- Recovery Strategies (1 record(s) found.)
- COSEWIC Annual Reports (1 record(s) found.)
- Consultation Documents (1 record(s) found.)
- Recovery Document Posting Plans (1 record(s) found.)
COSEWIC Status Reports
Response Statement - Large Whorled Pogonia (2013-01-03)This orchid is known historically from only 3 sites in Ontario, but it has not been seen since 1996 despite searches at two of the three previously known sites. The species requires rich, deciduous or mixed, moist forest on sandy soil with abundant humus; this habitat continues to decline in quality due to trampling and exotic plants and earthworms. It is possible that this species may still be extant in Canada since many orchids are known to have long dormancy periods and often occur in very low numbers.
COSEWIC Annual Reports
COSEWIC Annual Report - 2011-2012 (2012-10-05)Under Canada’s Species at Risk Act (SARA), the foremost function of COSEWIC is to “assess the status of each wildlife species considered by COSEWIC to be at risk and, as part of the assessment, identify existing and potential threats to the species”. COSEWIC held two Wildlife Species Assessment Meetings in this reporting year (September 1, 2011 to September 30, 2012) from November 21 to 25, 2011 and from April 29 to May 4, 2012. On February 3, 2012, an Emergency Assessment Subcommittee of COSEWIC also assessed the status of the Tri-colored Bat (Perimyotis subflavus), the Little Brown Myotis (Myotis lucifugus), and the Northern Myotis (Myotis septentrionalis). During the current reporting period COSEWIC assessed the status or reviewed the classification of 67 wildlife species. For species already found on Schedule 1 of SARA, the classification of 32 species was reviewed by COSEWIC and the status of the wildlife species was confirmed to be in the same category (extirpated - no longer found in the wild in Canada but occurring elsewhere, endangered, threatened or of special concern). The wildlife species assessment results for the 2011-2012 reporting period include the following: Extinct: 1 Extirpated: 4 Endangered: 29 Threatened: 10 Special Concern: 15 Data Deficient: 2 Not at Risk: 6 Total: 67 Of the 67 wildlife species examined, COSEWIC reviewed the classification of 49 species that had been previously assessed. The review of classification for 26 of those species resulted in a confirmation of the same status as the previous assessment (see Table 1a).