The Western Blue-eyed Grass or Californian Blue-eyed Grass, Sisyrinchium bellum, is the common blue-eyed grass of California and Oregon west of the Sierra Nevadas, its range extending south into Baja California. It grows as a perennial plant in open places where there is some moisture, particularly grassy areas, though it can also be found in woodlands and at altitudes up to 2400 metres. Like other species of blue-eyed grasses that are locally dominant, it is generally known simply as "Blue-eyed Grass" within its natural range.
The stems of the Western Blue-eyed Grass can be as long as 60 cm, though they are often shorter. Its leaves are grassy and tufted. The flowers are 1 to 2 cm in diameter and purplish-blue, varying somewhat in color from a true blue to a definite purple; occasional white-flowering plants are found. It flowers from March to July. Dried in air, its seeds weigh between 1 and 4 mg. After flowering, it dies to the ground and is dormant over the summer.
The Ohlone used an infusion of the roots and leaves as a cure for indigestion and stomach pain, and similar uses are recorded from other Native American peoples. Its chief modern use is as an ornamental plant, and it is available for planting in gardens. It is moderately hardy and will tolerate temperatures down to -12 degrees Celsius.
In parts of its range, Western Blue-eyed Grass has previously been classified as Sisyrinchium eastwoodiae, S. greenei and S. hesperium, but these names are now considered synonyms.