Stems 3-7 dm; herbage glabrous; lvs pale green, lanceolate or lance-oblong, 4-8 cm, commonly over a third as wide, rounded or broadly obtuse at the sessile base, the involucral ones more lance-ovate, closely ascending, enveloping the calyces; fls usually all terminal; cal-lobes linear-oblong or oblanceolate, mostly 4-12 mm, acuminate, hyaline-scarious below; cor 2.5-5 cm, pale below, generally suffused with blue upwards, narrowly open, its lobes acute, surpassing the obliquely triangular, entire to 1-toothed plaits by 3-5 mm; anthers connate. Wet meadows, especially on calcareous or otherwise nongranitic substrates; s. and w. Ont. to s. Sask., Minn., Wis. and n. Mich.; isolated stations in Me. and N.B. Aug., Sept. (G. linearis var. latifolia; Dasystephana grayi)
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.