Where is Small Whorled Pogonia (Isotria medeoloides)
located in the wild?
Isotria medeoloides inhabits semi-open, mesic forests of eastern North America. Mehrhoff (1988) describes these as mixed deciduous forests in second- or third-growth successional stages. Soils in sites with the orchid are highly acidic, and many are fragipans on shallow-to-bedrock (or shallow-to-clay) slopes of 8-22% where lateral water drainage from upslope sources occurs (NatureServe 2001), particularly in the northeastern part of its range. Occasionally, the orchid can be found in more calcium-rich sites, including limestone areas in New York, Missouri, and Ontario, where a more species-rich assemblage of herbaceous plants are associated with the orchid. In Georgia, the species is described from partially shaded gaps in mixed hardwood-conifer forests with an open understory and sparse herbaceous layer. Some sites have historically supported agriculture, and forest stands overlying Isotria medeoloides vary from 30 to over 75 years in age (von Oettingen 1992). The orchid is frequently found where leaf litter and decaying wood abound. Braided channels of vernal streams are promising places to search (Van Alstine et al. 1996). Recently, specific habitat models for the plant have been constructed using geographic information systems that combine features such as elevation, soil type, forest composition, and light availability, helping to better predict where the orchid might occur. Such a model by Casabona and Giles (2001) correctly predicted the majority of known locations for the orchid in Prince William Forest Park, Virginia. Sperduto and Congalton (1996) and the U. S. Fish and Wildlife Service (2001) have also refined the habitat \\\\\\\"search image\\\\\\\" for I. medeoloides, contributing to more precisely targeted searches. For example, nine new populations of I. medeoloides found in Maine and New Hampshire using Sperduto and Congalton's model. Evidence from field studies suggests that Isotria medeoloides responds favorably to increased light levels and that reproduction may be suppressed by a closing canopy (Mehrhoff 1980, 1988, Brackley 1991). Management to thin the canopy over subpopulations of the orchid in New Hampshire has stimulated flowering, reduced the proportion of plants entering dormancy, and has fostered a higher density of stems (New England Wild Flower Society 1998, Brumback 2003).
Isotria medeoloides is found along the Appalachian belt from Ontario through New England, south to Tennessee, Georgia, and South Carolina, and west to Michigan (NatureServe 2003).
States & Provinces:
Small Whorled Pogonia can be found in Connecticut, Delaware, District of Columbia, Georgia, Illinois, Maine, Maryland, Massachusetts, Michigan, Missouri, New Hampshire, New Jersey, New York, North Carolina, Ohio, Ontario, Pennsylvania, Rhode Island, South Carolina, Tennessee, Vermont, Virginia, West Virginia