nodding wild onion
Allium cernuum

Hardiness: Zones 4 to 8
Plant type: Herbaceous perennial
Height: 1- 1.5'
Spread: 3- 6"
Sun: Full sun, part shade
Water: Dry to medium
Bloom time: June to august
Bloom color: Pink
Soil: Average, well-draining soil

Notes: Attract a wide range of pollinators, especially bumblebees 

More information on this plant here.