Sisyrinchium angustifolium (Narrowleaf Blue-Eyed Grass)

Blue-eyed grass is a bit of a misnomer, this low-growing plant is closer in relation to an iris than any kind of grass. When not in flower, blue-eyed grass will blend in seamlessly like a typical lawn grass. But in spring it pops with starry blue/violet blooms with yellow centers, and continues to flower sporadically into summer. Flowers close up at night to preserve nectar.

The blooms attract sweat bees, bumble bees, bee flies, and syrphid flies as well as spring butterflies such as the Blue Azure.
Blue-eyed grass will expand by clumping, and will self-seed assuming there are enough compatible plants. Plant rhizomes are easy to dig up and divide in winter or early spring, like any iris. 

Blue-eyed grass will tolerate thin, poor and gravely soils, but does not like to dry out completely. Does not like to be heavily mulched. Can take very light foot traffic and mowing, but you may lose blooms and seed. Has potential to be a grass lawn alternative in moist areas.

This plant is a great alternative to liriope as a groundcover or walkway border, and it is not preferred by deer and rabbits. Use in woodland gardens with ephemerals, front borders of rain gardens, nearby to gutter downspouts, or areas where water drains temporarily. Higher sun means the plants need more moisture.