S7 Technical Assistance
Eastern prairie fringed orchid (Platanthera leucophaea)
How to determine if eastern prairie fringed orchid may be present in a project area
Northeastern Illinois counties: Cook, DuPage, Kane, Lake, McHenry and Will.
|Photo courtesy of Mike Redmer
As part of Step 2 of the S7 process, you checked the Illinois species list and found that eastern prairie fringed orchid is present in the county where your proposed project is located. The next step is to determine whether eastern prairie fringed orchid "may be present" in the action area of your proposed project. Below is guidance to help you make that determination.
Habitat: The eastern prairie fringed orchid (orchid) occurs in a wide variety of habitats, from wet to mesic prairie or wetland communities, including, but not limited to sedge meadow, fen, marsh, or marsh edge. It can occupy a very wide moisture gradient of prairie and wetland vegetation. It requires full sun for optimal growth and flowering, which ideally would restrict it to grass and sedge dominated plant communities. However, in some plant communities where there are encroaching species such as cattail and/or dogwood, the orchid may be interspersed or within the edge zones of these communities and thus can sometimes occur in partially shaded areas. The substrate of the sites where this orchid occurs include glacial soils, lake plain deposits, muck, or peat which could range from more or less neutral to mildly calcareous (Bowles et al. 2005, USFWS 1999). In some cases, the species may also occur along ditches or roadways where this type of habitat is present.
Processes that maintain habitats in early or mid-successional phases may be important in providing the sunny, open conditions required by the orchid (USFWS 1999). Sedge meadow and marsh habitats that support this orchid are usually early- or mid- successional because of past grazing, drainage, or soil disturbance. Patch disturbances that expose the soil to this orchid’s seeds, and reduce competition from established plants, may be needed for seedling establishment.
Hawkmoths are the pollinators of this orchid species. In Illinois the hawkmoth, Sphinx eremitus is a confirmed pollinator although there may be others. Eumorpha pandorus and Eumorpha achemon have been confirmed as pollinators in other states. Host plants for the caterpillars of Sphinx eremitus include various species of beebalm (Monarda spp.), mints (Mentha spp.), bugleweed (Lycopus spp.) and sage (Salvia spp.).
Follow the steps below to determine whether the eastern prairie fringed orchid may be present in the action area of your proposed project. This guidance is specific to Cook, Lake, McHenry, DuPage, Kane, and Will counties in northeastern Illinois.
1) Define the action area – all areas to be affected directly or indirectly by the Federal action and not just in the immediate area involved in the action. (For example: downstream areas, adjacent off-site wetlands, etc.)
2) Does the action area support any wet to mesic prairie or wetland
communities including, but not limited to sedge meadow, fen, or marsh edges?
If the answer is yes, go to number 3 (below). If the answer is no, conclude that “the eastern prairie fringed orchid is not present,” document your finding for your records or provide this information to the federal action agency. No further consultation is required.
3) Conduct a floristic quality assessment for the proposed project site during the growing season or use a previous assessment that is not more than three years old and was conducted during the growing season.
4) If any wetland in the action area is determined to be high quality, (a Native Floristic Quality Index of 20 or greater or a Native Mean C of 3.5 or greater) proceed to number 5 (below) or contact the Chicago Field Office for further consultation.
For wetlands that are not high quality, conclude that the "eastern prairie fringed orchid is not present," document your finding in your records or provide this information to the federal action agency.
5) Compare the plant species list generated for each high quality wetland with our Associate Plant Species List for the Eastern Prairie Fringed Orchid. If four or more associates are listed, then proceed to number 6. If not, high quality wetlands that support three or less eastern prairie fringed orchid associate plant species are unlikely to support eastern prairie fringed orchids. Conclude that “the eastern prairie fringed orchid is not present” and document your finding for your records or provide this information to the federal action agency. No further consultation is necessary for those wetlands.
6) The eastern prairie fringed orchid may be present in your action area. You may either assume that the eastern prairie fringed orchid is present and proceed to Step 3 of the Section 7 Consultation Process or conduct a field search during the bloom date of the orchid; June 28 through July 11. Because northeastern Illinois orchid populations bloom sporadically rather than all plants blooming at the same time, searches should be conducted on a minimum of three non-consecutive days within this time period. Please notify the Chicago Field Office before conducting your survey.
7) If you assume that the eastern prairie fringed orchid may be present in the action area or a field search proves that the orchid is present, the next step in the S7 Consultation Process is to determine whether the proposed action may affect any eastern prairie fringed orchids. Go to Step 3 of the S7 Consultation Process to begin that determination.
Please contact the U.S. Fish and Wildlife Service’s Chicago Illinois Field Office if you for more information or if you have any questions.
Chicago Illinois Field Office
1250 South Grove, Suite 103
Barrington, Illinois 60010
Phone: 847/381-2253, ext. 20
1Swink, F. and G. Wilhelm. 1994. Plants of the Chicago Region, 4th ed. Indiana Academy of Science, Indianapolis. 921pp.
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