Sisyrinchium angustifolium Mill.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
Species Description - Bright green, turning darker in drying; stems 1.5–5 dm, somewhat spreading, mostly not geniculate, thin and flattened, broadly winged, (2–)2.5–4 mm wide, the wings individually wider than the central part and minutely denticulate on the margin; lvs mostly 2–6 mm wide; spathes evidently peduncled from the axils of lf-like bracts, mostly not geniculate, the outer bract commonly 2–4 cm, its margins connate for (2.5–)3.5–6 mm at base, the inner bract evidently shorter, commonly 1.3–2.2 cm; tep blue, 7–10 mm; fr 4–6 mm; 2n=48. Meadows, grassy places, and damp woods; Nf. to Minn., s. to Fla. and Tex. (S. graminoides; S. gramineum)