Stems glabrous. Leaf widths varying throughout range for species. Corolla lobes reduced to a mucro or at most minutely triangular, less than 1 mm. 2n = 26 [C. L. Rork 1949].

Flowering late summer–fall. Moist, open woods, swamps, savannas, mesic to wet prairies, calcareous soils; 0–1700 m; Man., Ont., Que.; Conn., Ill., Ind., Iowa, Ky., Md., Mass., Mich., Minn., Mo., N.J., N.Y., N.Dak., Ohio, Pa., Vt., Va., W.Va., Wis.

Isolated populations of var. andrewsii in Colorado and Virginia are no longer extant. This species has probably also been extirpated from Vermont, where it had been restricted to calcareous sites in the western part of the state, and may also have been extirpated from Massachusetts. Reports from Rhode Island have been based on specimens of Gentiana clausa, and the provenance of an old specimen labeled as being from New Hampshire is doubtful. More recent reports from New Hampshire have been based on misidentified spec­imens of G. clausa (D. E. Boufford and K. Porter-Utley, pers. comm.; studies for this flora).