Herbs, singly or rarely in small clumps, short-rhizomatous, 4-25 cm. Stems pale grayish green, glaucous; scales 2-4, near soil line, white to light green. Leaves pale grayish green; blade elliptic-obovate, 17-85 × 8-40 mm, apex acuminate, glaucous when young. Flowers subsessile, without nectar and fragrance; sepals arching, green to light green, linear-oblanceolate, 12-25 × 2-3 mm; petals light green, oblanceolate, 12-18 × 2-4 mm; lip light yellowish green to pale greenish white, streaked with green, obovate, 11-16 × 4-5 mm, lateral lobes narrowly triangular, margins involute, middle lobe rounded, margins slightly revolute, undulate; callus yellowish green, longitudinal, becoming elongate, with fleshy, wartlike papillae toward apex; column 8-10 mm; ovary 10-15 mm; rostellar flap reduced. Capsules 12-28 × 2-10 mm; pedicel of mature capsule elongating to 5-17(-20, rarely) mm. 2n = 18. Flowering May--Jun; capsules mature fall. Acidic soils, in dry to mesic 2d-growth, deciduous or deciduous-coniferous forests; typically light to moderate leaf litter, open herb layer (occasionally in dense ferns), moderate to light shrub layer, relatively open canopy; frequently on flats or slope bases near canopy breaks; of conservation concern; 30--1000 m; Ont.; Conn., Del., Ga., Ill., Maine, Md., Mass., Mich., Mo., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., S.C., Tenn., Vt., Va. Isotria medeoloides should be sought in Alabama, Arkansas, Indiana, Kentucky, and West Virginia. Isotria medeoloides is self-pollinating (L. A. Mehrhoff 1983). Nonflowering plants commonly have a white, arrested floral bud (1-2 mm).