Isotria verticillata
Whorled pogonia
Image of Isotria verticillata

Photo by Ryan P. O'Connor 

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Key Characteristics

Small orchid (20-40 cm) of dry-mesic forests, swamp borders, and bogs; superficially similar to cucumber root (Medeola virginiana) with 5-6 whorled leaves, but stem glabrous and hollow; flower stalked with 3 long purple sepals and a pale green lip.

Status and Rank

  • State Status: T
  • State Rank: S2
  • Global Rank: G5


County NameNumber of OccurrencesYear Last Observed
Van Buren11963
Distribution map for Isotria verticillata

Updated 5/15/2018. Information is summarized from MNFI's database of rare species and community occurrences. Data may not reflect true distribution since much of the state has not been thoroughly surveyed.


The whorled pogonia is found in successional bogs in southern Lower Michigan, such as in alkaline kettleholes where bog succession is occurring with the advent of sphagnum and other acid-loving species. It also occurs in successional oak and red maple forest in lower slope position and in seasonally inundated, acid hardwood swamps with diverse microtopography (hummocks and hollows), within a matrix of upland oak forest.

Natural Community Types


For each species, lists of natural communities were derived from review of the nearly 6,500 element occurrences in the MNFI database, in addition to herbarium label data for some taxa. In most cases, at least one specimen record exists for each listed natural community. For certain taxa, especially poorly collected or extirpated species of prairie and savanna habitats, natural community lists were derived from inferences from collection sites and habitat preferences in immediately adjacent states (particularly Indiana and Illinois). Natural communities are not listed for those species documented only from altered or ruderal habitats in Michigan, especially for taxa that occur in a variety of habitats outside of the state.

Natural communities are not listed in order of frequency of occurrence, but are rather derived from the full set of natural communities, organized by Ecological Group. In many cases, the general habitat descriptions should provide greater clarity and direction to the surveyor. In future versions of the Rare Species Explorer, we hope to incorporate natural community fidelity ranks for each taxon.

Associated Plants

Black spruce, bog birch, larch, bog laurel, red maple, high-bush blueberry, leatherleaf, and sphagnum moss. In uplands, it may also occur with white oak, red maple, witch hazel, bracken fern, Pennsylvania sedge, wintergreen, starflower, blueberry, maple-leaved viburnum, Indian pipe, serviceberry, and Canada mayflower.


Very little is known of the population dynamics of this species, thus no specific management recommendations can be suggested. Monitoring and avoidance of cutting in the immediate area of colonies are recommended at this time. It like requires the maintenance of hydrology where it occurs in or near wetlands.

General Survey Guidelines

Random meander search covers areas that appear likely to have rare taxa, based on habitat and the judgement of the investigator.

Survey Methods

Page Citation

Michigan Natural Features Inventory. 2007. Rare Species Explorer (Web Application). Available online at [Accessed Aug 18, 2018]


Survey References

Technical References

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