It can be difficult to distinguish the different species of Blue-Eyed Grass. The white form of Prairie Blue-Eyed Grass (as illustrated in the above photograph) is quite similar to Sisyrinchium albidum (White Blue-Eyed Grass). Prairie Blue-Eyed Grass produces a single umbel of flowers from a single sessile spathe near the apex of a flowering stalk, while White Blue-Eyed Grass has two sessile spathes with separate umbels of flowers. Depending on the stage of development, from 1-2 bracts of the spathe will be observable while Prairie Blue-Eyed Grass is blooming, while White Blue-Eyed Grass will have 2-4 observable bracts of the spathe(s). The remaining bracts have not separated from the taller leafy bract at the apex of the stalk at the time of bloom, therefore they remain hidden. When Prairie Blue-Eyed Grass has pale blue to blue-violet flowers, it can be confused with other Sisyrinchium spp. Generally, Prairie Blue-Eyed Grass has more slender leaves and flowering stalks than these other species, and its spathes are always sessile (they never develop on long secondary stalks). The common name for this genus, Blue-Eyed Grass, is something of a misnomer because the flowers, whether white or blue, have yellow centers.