Stems 4-20 cm. Leaves mostly whorled at stem apex, some alternate on proximal stem; blades of distal leaves lanceolate to lanceolate-elliptic, 2.5-10 (-12) cm × 6-45 mm, widest at midlength, (proximal leaves abruptly much smaller, 0.1-0.6 cm × 0.3-1.5 mm, ± scalelike), apex acute to acuminate. Pedicels 1-3(-5), 1.5-4 cm, shorter than leaves, usually sparsely stipitate-glandular. Flowers: corolla white, 5.5-8(-10) mm, lobes ovate to narrowly lanceolate, apex acute to acuminate. 2n = 96. Flowering summer. Moist to wet coniferous forest, open heath lands, mature northern hardwood forests; 30-1100 m; St. Pierre and Miquelon; Alta., Man., N.B., Nfld. and Labr., N.S., Ont., P.E.I., Que., Sask.; Conn., Ill., Ind., Ky., Maine, Md., Mass., Mich., Minn., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., Tenn., Vt., Va., W.Va., Wis.
From Flora of Indiana (1940) by Charles C. Deam
In deep humus, usually in tamarack and birch bogs, under white pine in swamps, or in low woods which border the preceding habitats. Local but frequent to common where found.
Stem 1-2 dm, usually with a small scale-lf near the middle and a whorl of lanceolate, acuminate lvs 4-10 cm at the top; pedicels 1-few, 2-5 cm; sep lance-linear; cor 8-14 mm wide, its lobes slenderly acuminate and mucronate; 2n=96. Rich woods and bogs; Lab. and Nf. to Alta., s. to Pa., n. O., n. Ill., and Minn.; also on the coastal plain from Mass. to Va., and irregularly s. in the Appalachians to n. Ga. May, June. (T. americana)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.