Sisyrinchium angustifolium, commonly known as narrow-leaf blue-eyed-grass, is a herbaceous perennial growing from rhizomes, native to moist meadow and open woodland. It is the most common blue-eyed grass of the eastern United States, and is also cultivated as an ornamental.

Range: Eastern Canada and US, west to Texas and Minnesota, in meadows, low woods, and shorelines.

Height: 15–50 centimetres (6–20 in). Stem: broadly winged, 2–4 millimetres (0.08–0.16 in) wide, usually branched. Leaves: 2–6 millimetres (0.08–0.24 in) wide. Tepals: 6, blue, 7–10 millimetres (0.3–0.4 in), each tipped with a sharp point, veined, and darkening toward central yellow patch.