10. Isotria Raf. (whorled pogonia)

Plants lacking rhizomes, the roots fascicled from the base of the flowering stem, fibrous or somewhat fleshy. Flowering stems glabrous, somewhat glaucous, hollow, with 1 or 2 flowers at the tip. Leaves 5 or 6, in a single whorl near the tip of the flowering stem, 3–5(–8) cm long, elliptic to obovate, green, glabrous. Sepals spreading, all similar. Lateral petals curved inward and overlapping over the column. Lip 3‑lobed, positioned parallel to the column. Stamen 1, staminodes lacking. Capsules erect, 18–30 mm long, elliptic in outline, strongly ribbed. Two species, North America.

Vegetative plants of Isotria might be confused with those of the Indian cucumber root, Medeola virginiana L. (Liliaceae). The latter species can be distinguished by its nonglaucous stems that are solid rather than hollow and have cobwebby pubescence.