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Service in the Midwest


The Midwest Region includes Illinois, Indiana, Iowa, Michigan, Minnesota, Missouri, Ohio and Wisconsin. Find a location near you.


The Midwest Region includes Illinois, Indiana, Iowa, Michigan, Minnesota, Missouri, Ohio and Wisconsin.
Find a location near you »

Associate Plant Species List for the Eastern Prairie Fringed Orchid in Northeastern Illinois

PDF Version


After conducting a Floristic Quality Assessment, if a site has already been determined to be high quality (Native FQI > or = 20, or Native Mean C > or = 3.5) then compare the plant species list from the site to the list below.  If 4 or more species from this list are present at the site, then we recommend conducting a search for the eastern prairie fringed orchid (Platanthera leucophaea, orchid hereafter) during its bloom period, approximately June 28 to July 11.


We have noticed that in northeastern Illinois orchid populations bloom sporadically rather than all plants blooming at the same time.  Because of this pattern, and small population numbers, it is possible to conduct an orchid search and not detect orchids even when they are present.   For this reason we recommend conducting the orchid search on at least 3 non-consecutive days during its bloom period.  Using this approach, we could be more confident of negative survey results.


Andropogon gerardii – big bluestem
Apocynum sibiricum – prairie Indian hemp
Aster ericoides – heath aster
Aster novae-angliae – New England aster
Aster simplex – panicled aster

Carex stricta - tussock sedge
Carex sp.
Calamagrostis canadensis – blue joint grass
Cassia fasciculata – partridge pea
Eupatorium perfoliatum – common boneset
Galium obtusum – wild madder
Gentiana puberulenta – prairie gentian
Helianthus grosseserratus – sawtooth sunflower
Iris virginica shrevei – blueflag iris
Liatris aspera – rough blazing star
Liatris spicata – marsh blazing star / gayfeather
Lycopus americanus – common water horehound
Mentha arvensis villosa – wild mint
Pycnanthemum virginiana – common mountain mint
Solidago gigantea – late goldenrod
Solidago graminifolia - common grass-leaved goldenrod or Solidago graminifolia nuttallii – hairy grass-leaved goldenrod 
Sorghastrum nutans – Indian grass
Tradescantia ohiensis – common spiderwort


Dufrene, M. & P. Legendre.  1997.  Species assemblages and indicator species: the need for a flexible asymmetrical approach. Ecological Monographs 67:345-366.


Wilhelm, G. and L. Rericha. 2017. Flora of the Chicago Region. A Floristic and Ecological Synthesis. Indiana Academy of Science, Indianapolis. 1392 pp.


USFWS 2009.  Unpublished data from MS thesis. Restoration of the Eastern Prairie Fringed Orchid (Platanthera leucophaea): Natural Pollinators and the Abundance of Larval Host Plants by Cathy Pollack.


Back to Eastern Prairie Fringed Orchid S7 Guidance page


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