Plants and Animals

Isotria verticillata Whorled pogonia

species photo
Ryan P. O'Connor
species photo
Ryan P. O'Connor
species photo
Ryan P. O'Connor

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

US Status:
State Status: T - Threatened (legally protected)
Global Rank: G5 - Secure
State Rank: S2 - Imperiled

Occurrences

CountyNumber of OccurrencesYear Last Observed
Barry11966
Berrien11966
Calhoun22006
Eaton21966
Genesee11840
Gratiot21894
Kalamazoo21935
Kalkaska12013
Kent21979
Montmorency11943
Newaygo12013
Saginaw21991
Van Buren11963
Washtenaw11990

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.

Habitat

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.

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.

Management Recommendations

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.

Survey Methods

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

  • Meander search

    • Survey Period: From fourth week of May to second week of June

References

Survey References

  • Elzinga, C.L., D.W. Salzer, and J.W. Willoughby. 1998. Measuring and Monitoring Plant Populations. The Nature Conservancy and Bureau of Land Management, Denver. BLM Technical Reference 1730-1. 477pp.
  • Goff, G.F., G.A. Dawson, and J.J. Rochow. 1982. Site examination for Threatened and Endangered plant species. Environmental Management 6(4): 307-316
  • Nelson, J.R. 1984. Rare Plant Field Survey Guidelines. In: J.P. Smith and R. York. Inventory of rare and endangered vascular plants of California. 3rd Ed. California Native Plant Society, Berkeley. 174pp.
  • Nelson, J.R. 1986. Rare Plant Surveys: Techniques For Impact Assessment. Natural Areas Journal 5(3):18-30.
  • Nelson, J.R. 1987. Rare Plant Surveys: Techniques for Impact Assessment. In: Conservation and management of rare and endangered plants. Ed. T.S. Elias. California Native Plant Society, Sacramento. 8pp.

Technical References

  • Case, F.W., Jr. 1987. Orchids of the Western Great Lakes Region. Revised ed. Cranbrook Institute of Science, Bull. 48. 251pp.
  • Flora of North America Editorial Committee. 2002. Flora of North America, North of Mexico. Volume 26: Magnoliaphyta: Liliidae: Liliales and Orchidales. Oxford University Press, New York. 723pp.
  • Gleason, H. A., and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. Second edition. The New York Botanical Garden, Bronx. 910pp.
  • Godfrey, R.K. and Wooten. 1981. Aquatic and Wetland Plants of Southeastern United States. Dicotyledons. University of Georgia Press, Athens. 712pp.
  • Gray, A. 1950. Gray's Manual of Botany; eighth ed. Van Nostrand Reinghold, New York. 1632pp.
  • Holmgren, N.H. 1998. Illustrated Companion to Gleason and Cronquist's Manual. Illustrations of the vascular plants of Northeastern United States and adjacent Canada. New York Botanical Garden, Bronx. 937pp.
  • Homoya, M.A. 1993. Orchids of Indiana. Indiana University Press, Bloomington. 276pp.
  • Luer, C.A. 1975. The Native Orchids of the United States and Canada, Excluding Florida. Native Orchids U.S. & Canada. Barrons Educational Series, Hauppauge.
  • Swink, F. and G. Wilhelm. 1994. Plants of the Chicago Region, 4th ed. Indiana Academy of Science, Indianapolis. 921pp.
  • Voss, E. G. 1972. Michigan Flora. Part I. Gymnosperms and Monocots. Bulletin of the Cranbrook Institute of Science and University of Michigan Herbarium. 488pp.
  • Whiting, R.E. and P.M. Catling. 1986. Orchids of Ontario. The CanaColl Foundation, Ottawa. 169pp.