This is widespread in grassland swales across the Great Plains, and scattered thinly at disjunct sites further east. Typical soils are base-rich, dry in summer but damp to wet in winter. The only known sizeable population in Ky., with 10-100 plants, is at "Pine Creek Barrens" (BULL). Most records are from groups of 1-10 plants, from which colls. have not generally yet been accessed; see KSNPC for details. S. magnicamporum differs from odorata, cernua and ochroleuca as follows (FNA 26, W): flowers abruptly nodding from base (versus ascending to nodding) and gaping (versus urceolate to gaping), mostly white (versus white, pale yellowish or greenish); lateral sepals free and spreading, often over top of flower (versus more or less appressed); leaves absent at flowering (versus present). Peak flowering in Ky. and elsewhere (Catling & Brown 1983) tends to be 2-3 weeks later than cernua: mostly mid to late Oct versus late Sep to mid Oct. However, clear distinction from cernua is sometimes difficult or impossible using available keys. For example, a solitary plant was found in full flower on 17 Oct 2015, between a road and pond near Clay City in POWE. It keyed to magnicamporum in all characters, but there are no previous records from this locality, where cernua has previously been seen on several occasions. In contrast, FNA 26 stated that: "Gene flow from Spiranthes magnicamporum [into cernua] generates cytogenetically based peloria [unusual regularity in flowers], a common element in portions of the prairie region."