Small whorled pogonia

Listed: 9/9/1982

Status since listing: Increased

The small whorled pogonia (Isotria medeoloides) is a rare orchid of relatively open eastern deciduous and coniferous forests [1]. It formerly occurred in 48 counties in 16 states and Canada. When placed on the endangered species list in 1982, it was thought to exist in only 17 counties in 10 states and at one site in Ontario, Canada. By 1985 it was known from 34 sites, by 1991 it was known from 86 sites in 15 states, and by 1993 it was known from 104 sites in 15 states. The 104 sites included 66 in the Appalachian Mountains in New England and northern coastal Massachusetts: Maine (17), New Hampshire (42), Massachusetts (five), Rhode Island (one), Connecticut (10); 13 in the Coastal Plain and Piedmont: New Jersey (three), Delaware (one), Virginia (nine); 18 in the Southern Appalachians: North Carolina (five), South Carolina (four), Georgia (eight), Tennessee (one); and seven disjunct populations: Pennsylvania (three), Ohio (one), Michigan (one), Illinois (one), Ontario (one). In 1993 it was still extirpated from Vermont, New York, Maryland, Missouri and the District of Columbia. Since 1993, additional small populations were discovered in the southern portion of the pogonia's range, and in New Hampshire and Maine [4]. In 1999, a new population was documented for the first time in West Virginia.

As of 1998, plants had not been found at the Ontario site since the sighting of a single individual in 1989 [3].

The 1992 revised recovery plan stated that downlisting to "threatened" status should occur when 25% of the viable populations known as of 1992 are protected, and proportionally distributed throughout the species range [2]. The species was downlisted to threatened in 1994 based on finding that 23% of all sites were viable and protected, and 62% of viable populations were protected [1]. Though quantitative population trend data are lacking, we classify the pogonia as "increased since listing" because the downlisting rule in unambiguous about its status having improved independent of newly discovered populations.

[1] U.S. Fish and Wildlife Service. 1994. Final rule to reclassify the plant Isotria medeoloides (small whorled pogonia) From endangered to threatened. U.S. Fish and Wildlife Service. October 6, 1994 (59 FR 50852-50857).