If you are planning to develop property in Northern Virginia that has mature hardwood forest with an open understory, you may need a survey for the small whorled pogonia (Isotria medeoloides) between June 1 and July 20 – or your wetlands permitting may be delayed up to a year!

The small whorled pogonia, a tiny orchid (see photo – note 35mm film canister for scale), is federally listed as “threatened” and state listed as “endangered.” As a result, it is protected by both federal and state endangered species laws, and the U.S. Army Corps of Engineers (COE) and Virginia Department of Environmental Quality (DEQ) must consider potential impacts to this species before issuing permits to impact wetlands and other jurisdictional waters.

Virginia counties with records of the small whorled pogonia include Prince William, Stafford, Spotsylvania, Madison, Caroline, Gloucester, James City, Lee, Wise, and Fairfax. Most colonies have been found in Stafford and eastern Prince William Counties, and WSSI recorded Fairfax County’s first documented occurrence of small whorled pogonia during a search conducted on Fort Belvoir property in 2005. While, to the best of WSSI's knowledge, this species has still not been recorded in Loudoun or Fauquier Counties, the discovery of this species in Madison, Lee, and Wise Counties over the past few years indicates that the species is not restricted to the Virginia Coastal Plain and eastern Piedmont.

According to Kim Marbain of the U.S. Fish and Wildlife Service (FWS), the FWS generally recommends that surveys be conducted on any site within a county of known small whorled pogonia occurrence if suitable habitat is present. Prior to the discovery of the small whorled pogonia in Fairfax County, at the request of the FWS, the COE has in the past required small whorled pogonia surveys on several sites in Fairfax County before issuing Section 404 permits. Now that the species has been discovered in Fairfax County, it is likely that the COE will require small whorled pogonia surveys on all Fairfax County sites with potentially suitable habitat.

Preliminary (and relatively inexpensive) site evaluations to determine whether potentially suitable habitat is present may be conducted any time of the year; and for some sites, a habitat evaluation may be all that is necessary to confirm absence of the species. However, because above-ground structures (e.g., stems, leaves, and flowers) of the small whorled pogonia are most apparent in late spring and summer, surveys for this species in suitable habitat areas should be conducted between June 1 and July 20 (in Virginia localities from Caroline County north) according to FWS guidelines.

Due to this limited survey "window," proper planning by project proponents on sites having suitable habitat is critical. Failure to have a pogonia survey conducted during the appropriate season could potentially result in wetlands permitting delays of up to a year! Therefore, project proponents of Virginia sites within the species' range that will require wetlands permitting should also consider having a small whorled pogonia habitat evaluation (or survey) conducted as early in the development process as possible, preferably in the June 1 to July 20 time frame, to ensure development schedule compliance. It should be noted that surveys are valid for a period of two years, and if the site is not developed within two years of the completion of the survey, the USFWS may request that the site be re-surveyed.

In Virginia, small whorled pogonias generally occur in upland mixed hardwood forests, usually dominated by oaks, although it does show several habitat affinities that allow for a more refined evaluation of habitat quality on a given site. Most occupied sites are on land that was cleared for agriculture and farmed in the past, then allowed to return to a forested state, with canopy trees approximately 40 to 80 years old. Other characteristics common to most inhabited sites include relatively open understory vegetation with sparse herbaceous ground cover, and nearly level to gently sloping topography with northern or eastern exposure. The presence of standing dead trunks, decaying woody debris, sandy loam soils with low pH and low nutrient content, and scattered gaps in the tree canopy are also typical of sites where the small whorled pogonia is known to occur.

The plant may grow up to 10 inches tall, but most individuals are much smaller. They have five or six pale green leaves in a whorl at the top of a smooth pale green stem. The small green flower (usually one, occasionally two) sits atop the center of this whorl of leaves; although in any given year, many (or most) individuals in a colony do not produce any flowers.

Conducting an ETS Survey

Several other species, including the much more abundant and widespread common whorled pogonia (Isotria verticillata) and Indian cucumber root (Medeola virginiana), can appear very similar to the small whorled pogonia. Therefore, experience is needed to distinguish individuals of these species. As a result, FWS maintains a list of consultants and botanists with sufficient experience conducting small whorled pogonia surveys to reliably survey a site for this species.

WSSI has conducted a number of habitat evaluations and surveys for the small whorled pogonia, and four of WSSI's scientists are included on the FWS's list of small whorled pogonia survey contacts.

For further information about this topic, or to have WSSI conduct a small whorled pogonia habitat evaluation or survey on your site, feel free to contact Mark Headly, PWS, PWD, Craig Tumer, PWS, PWD, or Laura Giese, PhD, CF, PWS, PWD.

Or you may reach any of our staff at 703.679.5600.