Plants and Animals

Cypripedium candidum White lady slipper

species photo
Susan R. Crispin
species photo
Dennis A. Albert
species photo
Donald H. Les
species photo
Michael R. Penskar

Key Characteristics

Small orchid (20-30 cm) of prairie fens and lakeplain prairies; leaves narrowly elliptic; flower a small ivory-white pouch-like slipper.

Status and Rank

US Status: No Status/Not Listed
State Status: T - Threatened (legally protected)
Global Rank: G4 - Apparently secure
State Rank: S2 - Imperiled


CountyNumber of OccurrencesYear Last Observed
Allegan 1 2021
Barry 1 1969
Berrien 7 2007
Branch 2 1970
Calhoun 2 2005
Cass 7 2013
Clinton 1 1884
Genesee 1 1997
Hillsdale 5 2020
Huron 1 1990
Ingham 1 2009
Ionia 1 1884
Jackson 9 2010
Kalamazoo 9 2022
Kent 2 2004
Lenawee 3 2001
Livingston 14 2016
Oakland 15 2019
St. Clair 1 1991
St. Joseph 1 2007
Tuscola 2 1994
Van Buren 3 2022
Washtenaw 20 2016

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.


Found in alkaline wetlands in southern Lower Michigan, particularly prairie fens and occasionally in lakeplain wet and wet-mesic prairies along coastal areas in the Thumb region.

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

Trees: Larix laricina (tamarack).

Shrubs: Betula pumila (bog birch), Cornus spp. (dogwoods), Dasiphora fruticosa (shrubby cinquefoil), Rhamnus alnifolia (alder-leaved buckthorn), Salix spp. (willows), and Spiraea alba (meadowsweet).

Ground layer: Andropogon gerardii (big bluestem), Arnoglossum plantagineum (prairie Indian-plantain), Calamagrostis canadensis (blue-joint grass), Campanula aparinoides (marsh bellflower), Carex interior (inland sedge), C. sterilis (sterile sedge), C. stricta (tussock sedge), C. tetanica (rigid sedge), Cicuta maculata (water hemlock), Cladium mariscoides (twig-rush), Eleocharis elliptica (golden-seeded spike-rush), Eupatorium perfoliatum (common boneset), Eutrochium maculatum (Joe-pye-weed), Juncus spp. (rushes), Lysimachia quadriflora (whorled loosestrife), Parnassia glauca (grass-of-parnassus), Pilea fontana (bog clearweed), Platanthera leucophaea (prairie fringed-orchid), Pycnanthemum virginianum (Virginia mountain mint), Rudbeckia hirta (black-eyed Susan), Schizachyrium scoparium (little bluestem), Schoenoplectus acutus (hardstem bulrush), S. pungens (three-square), Solidago ohioensis (Ohio goldenrod), S. riddellii (Riddell's goldenrod), Sorghastrum nutans (Indian grass), Sporobolus heterolepis (prairie dropseed), and Thelypteris palustris (marsh fern).

Management Recommendations

Requires protection of hydrology, groundwater source, and natural disturbance regime. This species benefits from fen management that includes prescribed fire and brush removal, which maintains open habitat and reduces competing woody vegetation. Control/remove invasive species, especially glossy buckthorn and purple loosestrife. Protect habitat from being drained and developed.

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 third week of May to third week of June


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.
  • Coffin, B. and L. Pfannmuller, eds. 1988. Minnesota's Endangered Flora and Fauna. University of Minnesota Press, Minneapolis. 473pp.
  • 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.
  • 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.
  • 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.