Great Plains Ladies' Tresses

Spiranthes magnicamporum Sheviak

Spiranthes magnicamporum in flower
Steven Daniel

Monocotyledoneae (Monocots)
Orchidaceae (Orchid Family)
State Protection
Listed as Endangered by New York State: in imminent danger of extirpation in New York. For animals, taking, importation, transportation, or possession is prohibited, except under license or permit. For plants, removal or damage without the consent of the landowner is prohibited.
Federal Protection
Not Listed
State Conservation Status Rank
Critically Imperiled in New York - Especially vulnerable to disappearing from New York due to extreme rarity or other factors; typically 5 or fewer populations or locations in New York, very few individuals, very restricted range, very few remaining acres (or miles of stream), and/or very steep declines.
Global Conservation Status Rank
Vulnerable globally, or Apparently Secure - At moderate risk of extinction, with relatively few populations or locations in the world, few individuals, and/or restricted range; or uncommon but not rare globally; may be rare in some parts of its range; possibly some cause for long-term concern due to declines or other factors. More information is needed to assign either G3 or G4.


Did you know?

The epiphet “magnicamporum’ means ‘of the Great Plains’ and is a direct reference to this species preferred habitat. When first described it was thought to only occur in the Great Plains region of North America, with the eastern most population occurring in Ohio. Recently, there have many more populations discovered expanding the species known range. The NY populations are now the eastern most known populations in the North America.

State Ranking Justification

There are only 4 known populations of Spiranthes magnicamporum in New York State. All populations are on protected land, but range in size from a few individuals to a few hundred and seem to fluctuate in number year to year.

The first population in NY was discovered as recently as 2014 by Daniel Brunton (Brunton 2015). This was followed shortly after by the discovery of two additional populations by Henry Steger and Steven Daniel in 2015 (Brunton 2015, Daniel and Johnson 2018). A new population was found as recently as 2020, by Rich Ring (New York Natural Heritage Program 2022), indicating we may not know the full extent of this species in New York yet.

Short-term Trends

The short-term trend of this species appears stable. All four known populations are on protected lands and appear to have relatively stable populations based on recent field surveys.

Long-term Trends

The long-term trend of this species in New York is not currently known, given its recent discovery in the state and the recent discovery of additional populations. Return visits to populations show some fluctuation in population numbers, but more time and surveys are needed to determine any demographic trends.

Conservation and Management


Primary threats to this orchid are succession from open herbaceous to woody plant-dominated communities and suppression or alteration of natural disturbance regimes that maintain the early successional habitat. Expansion of nearby invasive species may also threaten these populations, along with disturbances from river dredging, infrastructure maintenance, and foot traffic.

Conservation Strategies and Management Practices

Maintain early-successional habitats and implement appropriate disturbance regimes where they are not occurring naturally. Sites should be monitored for the encroachment of woody plants and invasive species. Review infrastructure projects that may affect adjacent populations to ensure impacts are minimal and/or help maintain early successional habitats in an appropriate manner (i.e. placement of dredge spoils, timing and volume of dam releases).

Research Needs

More demographic studies are needed to understand annual fluctuations in population size and help guide conservation planning. Research is also needed to determine the appropriate type and timing of disturbance regimes for conservation of existing populations and existing habitats. Additional surveys of likely habitat present in New York are needed to better define this species range and habitat preferences in the state.

Curiously, there was a report in Jefferson County of a population intermediate between Spiranthes cernua and S. magnicamporum (Brunton 2015). When S. magnicamporum was first described, it was thought that these species could not hybridize, despite the authors manually cross-pollinating individuals of S. cernua and S. magnicamporum (Sheviak 1973). More research is needed to determine the identity of these apparently intermediate plants.



In New York the Great Plains laddies-tresses are found in open alvar grasslands; on dredge/fill with poor soils and limited woody vegetation; in open cobbly areas with little soil in flooded and ice-scoured flat riverside meadows (New York Natural Heritage Program 2022), alvars (Hough 2022), and alvar habitat; open, low-lying, sparsely vegetated meadow (Brunton 2015). In other parts of its range it is noted as occuring in wet calcareous meadows, fens, moist to dryish prairies and prairie-like habitats, in calcareous soils (Reznicek 2011), dry to wet prairies and fens (FNA 1993) and dry prairies and related grasslands; dry ridge tops; proven a distinct calciphile (Sheviak 1973).

Associated Ecological Communities

  • Alvar pavement grassland (guide)
    This community consists of exposed, flat limestone or dolostone pavement with grassy or mossy patches interspersed throughout. Some examples may be solely grassland with no pavement.
  • Cobble shore wet meadow (guide)
    A community that occurs on the cobble shores of lakes and streams where the substrate is moist from seepage or intermittent flooding. These communities are likely to be scoured by floods or winter ice floes, but there is apparently no significant accumulation of pack ice.

Associated Species

  • Achillea millefolium (yarrow)
  • Antennaria neglecta (field pussy-toes)
  • Asclepias syriaca (common milkweed)
  • Betula populifolia (gray birch)
  • Bromus ciliatus (fringed brome)
  • Carex eburnea (bristle-leaved sedge)
  • Danthonia spicata (poverty grass)
  • Daucus carota (wild carrot)
  • Equisetum variegatum
  • Euphrasia stricta (upright eye-bright)
  • Euthamia graminifolia (common flat-topped-goldenrod)
  • Helianthus maximiliani (Maximilian's sunflower)
  • Lobelia kalmii (Kalm's lobelia)
  • Lythrum salicaria (purple loosestrife)
  • Odontites vernus
  • Phragmites australis (old world reed grass, old world phragmites)
  • Poa compressa (flat-stemmed blue grass, Canada blue grass)
  • Potentilla anserina ssp. anserina (common silverweed)
  • Schoenoplectus tabernaemontani (soft-stemmed bulrush)
  • Symphyotrichum novae-angliae (New England-aster)
  • Symphyotrichum pilosum var. pringlei (Pringle's-aster)
  • Vicia tetrasperma (lentil vetch)


New York State Distribution

In New York, this species is only known from northern Jefferson and St. Lawrence Counties.

Global Distribution

Eastern Great Plains, Great Lakes and Midwest regions, with disjunct populations in Utah, Colorado, New Mexico and Alabama-Mississippi (Luer 1975). Also into Ontario and Manitoba (Kartesz unpublished data 1995).

Identification Comments

General Description

The Great Plains ladies-tresses is a perennial orchid species that can be separated from other similar Spiranthes by its conspicuous lack of leaves at the time of flowering, strong vanilla-like scent, and late flowering time. The lip petal is centrally and marginally thickened with yellow-orange center and reduced basal glands. The flowers are generally perpendicular to the stem giving the inflorescence a scalariform (uniform and ladder-like) appearance.

Identifying Characteristics

Spiranthes magnicamporum can range from 7-60 cm in height. The leaves are basally disposed, ca. 16 x 1.5 cm, and senesce two to several weeks prior to the appearance of the inflorescence, leaving behind 4-8 leaf sheaths. The inflorescence is tightly spiraled creating a scalariform (uniform and ladder-like) appearance with 3-4 flowers per cycle. The rachis is pubescent with stalked glands. Sepals are 5-14 mm, lateral sepals are free and widely spreading, often ascending, and sometimes loosely incurved. Petals are 4.9-13 mm long. The central portion of the lip is yellow and thickened with reduced basal glands and nearly entire margins that are sometimes crenulate, but without much crisping.

Best Life Stage for Proper Identification

This species is best identified when flowering.

Similar Species

This species can be separated from other similar Spiranthes by its conspicuous lack of leaves at the time of flowering, strong vanilla-like scent, and late flowering time. The lip petal is centrally and marginally thickened with a yellow-orange center and reduced basal glands. The flowers are generally perpendicular to the stem giving the inflorescence a scalariform (uniform and ladder-like) appearance.

Similar species such as S. cernua, S. ochroleuca, and S. odorata all retain their basal and cauline leaves at the time of flowering. S. magnicamporum typically flowers from September to October in New York, starting just as S. cernua is past its prime. The lip petal in S. cernua is thin and almost pure white, as opposed to the centrally thickened and yellow-orange center of S. magnicamporum. The lips of S. odorata and S. ochroleuca are also yellow, however the lip margins in S. ochroleuca are thin and not centrally thickened. In S. odorata, the lip is both centrally and marginally thickened, but also has well developed basal nectar glands, as opposed to the reduced nectar glands of S. magnicamporum.

Best Time to See

This species flowers from mid-September into mid-October.

  • Vegetative
  • Flowering
  • Fruiting

The time of year you would expect to find Great Plains Ladies' Tresses vegetative, flowering, and fruiting in New York.

Great Plains Ladies' Tresses Images


Great Plains Ladies' Tresses
Spiranthes magnicamporum Sheviak

  • Kingdom Plantae
    • Phylum Anthophyta
      • Class Monocotyledoneae (Monocots)
        • Order Orchidales
          • Family Orchidaceae (Orchid Family)

Additional Resources


Brunton, Daniel F. 2015. Great Plains Ladies-tresses (Spiranthes magnicamporum) Discovered in New York State. New York Flora Association Quarterly Newsletter. Vol. 26(1), pp 1-3. New York Flora Association.

Flora of North America Editorial Committee. 2002. Flora of North America, North of Mexico. Volume 26. Magnoliophyta: Liliidae: Liliales and Orchidales. Oxford University Press, New York. 723 pp.

Gleason, Henry A. and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. The New York Botanical Garden, Bronx, New York. 910 pp.

Hough, Michael. 2022. Spiranthes sheviakii, a new orchid species. Mitchelliana Vol. 33(3), pp 1-9. New York Flora Association.

Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.

Luer, C.A. 1975. The Native Orchids of United States and Canada Excluding Florida.

MICHIGAN FLORA ONLINE. A. A. Reznicek, E. G. Voss, & B. S. Walters. February 2011. University of Michigan. Web. October, 12, 2022

New York Natural Heritage Program. 2022. New York Natural Heritage Program Databases. Albany, NY.

New York Natural Heritage Program. 2024. New York Natural Heritage Program Databases. Albany, NY.

Pace, Matthew C. 2020. The Orchidaceae of northeastern North American: Systematics, evolution, diversity, and conservation. Memoirs of the Torrey Botanical Society. Vol. 29, Historical Issue: 150 years of the Torrey Botanical Society (2020), pp. 156-189.

Sheviak, Charles J. 1973. A new Spiranthes from the grasslands of central North America. Botanical Museum Leaflets, Harvard University. Vol. 23(7) 285-297. Harvard University Herbaria.

Werier, David, Kyle Webster, Troy Weldy, Andrew Nelson, Richard Mitchell†, and Robert Ingalls†. 2022 New York Flora Atlas. [S. M. Landry and K. N. Campbell (original application development), USF Water Institute. University of South Florida]. New York Flora Association, Albany, New York.


About This Guide

This guide was authored by: Kyle J. Webster

Information for this guide was last updated on: March 6, 2023

Please cite this page as:
New York Natural Heritage Program. 2024. Online Conservation Guide for Spiranthes magnicamporum. Available from: Accessed June 23, 2024.