Blue-eyed Grass - Sisyrinchium montanum

Despite its common name, Blue-eyed Grass is a diminutive member of the Iris family. It is hardy and takes poor soil in stride.  I first encountered them growing on a gravel berm around petroleum storage tanks where it didn't look like plant life could rightfully exist.  The Blue-eyed Grass was perfectly happy growing in bare dry gravel.  It handles competition quite well and readily spreads via underground rhizomes.  It can naturalize into lawns where it looks like grass, but hold off on the mowing to enjoy the bright blue spring flowers with yellow centers.  
 
The May or June flowers open in the morning and close in the evening.  They are a great early nectar source for our native bees and bloom before most other plants.  These small 8" to 12" plants like full sun and well-drained soil, but will grow in loam, clay, or sand.  They are especially striking planted in clumps.