Volume 25, Number 8    April 18, 2017

 

It's Almost Pogonia Season!

small whorled pogonia

small whorled pogonia

Summer is on its way and Wetland Studies and Solutions, Inc. (WSSI) is gearing up for another season of small whorled pogonia (Isotria medeoloides) surveys. If you are planning to develop property in Virginia that has mature hardwood forest with an open understory, your site may need a survey for the small whorled pogonia. The field survey "window" for the small whorled pogonia is narrow; searches can only be conducted June 1 – July 20 in northern Virginia and May 25 – July 15 in southern Virginia (south of Caroline County). Schedule now and avoid critical delays in obtaining your wetlands permit.

The small whorled pogonia is a very small orchid that is federally listed as "threatened" and state listed in Virginia 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. 

According to the U.S. Fish and Wildlife Service (FWS), the small whorled pogonia has been recorded within 20 localities¹ in Virginia and has been extirpated from Maryland. Most colonies have been found in Stafford and eastern Prince William Counties, and WSSI recorded the first documented occurrence of the small whorled pogonia in Fairfax County 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.

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. In recent discussions, the FWS indicated that it would continue to recommend searches for small whorled pogonias on wooded properties in the vicinity of Fort Belvoir in southeastern Fairfax County but not elsewhere in the County.

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 and distinctive 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, and between May 25 and July 15 in Virginia localities south of Caroline County.

Due to this limited survey "window," proper planning for 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 managers 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 FWS-specified timeframe, to ensure development schedule compliance. It should also 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 FWS may request that the site be re-surveyed.

Plant Habitat and Characteristics

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 and 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 gentle to moderate 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 (most individuals are much smaller) and has 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 many of WSSI's scientists are included on the FWS list of approved small whorled pogonia surveyors.

For further information about this topic or to have WSSI conduct a small whorled pogonia habitat evaluation or survey on your site, please contact Ben Rosner, Beth Clements, Mark Headly, Jennifer Van Houten, or Jennifer Feese.


1. The following counties have documented Isotria medeoloides (small whorled phogonia): Appomattox, Bedford, Buckingham, Caroline, Craig, Fairfax, Floyd, Gloucester, James City, King William, Lee, Madison, New Kent, Pittsylvania, Prince William, Spotsylvania, Stafford, Wise and York, as well as the City of Williamsburg. Localities where Isotria medeoloides has not been documented but may contain potential habitat include Amherst, Botetourt, Campbell, Charles City, Essex, Franklin, Henrico, King George, Roanoke, and Rockbridge.


Check out past issues in the Field Notes Archive.

Reading someone else's copy of Field Notes?
Click here to sign up for our mailing list.